The United Nations and several countries called Thursday for an end to Russia's war in Ukraine, with little mention of reviving the two countries' apparently stalled peace talks.

"Russia's invasion of Ukraine is a violation of its territorial integrity and of the Charter of the United Nations," said UN Secretary-General Antonio Guterres at a Security Council meeting organized by the United States.

"It must end for the sake of the people of Ukraine, Russia, and the entire world," he added.

Guterres recently visited Moscow and Kyiv to advocate for the evacuation of civilians from the battered port city of Mariupol, from where several hundred people have been able to escape since the weekend.

The majority of the Security Council's members, including China, the United States, Ireland, France and Mexico called for an end to the months-old conflict. 

The Chinese ambassador to the UN Zhang Jun underscored that only diplomacy would end the fighting, criticizing arms shipments to Ukraine. 

His Kenyan counterpart Martin Kimani called for Guterres' mediation. 

"Every opportunity must be used to achieve peace," said Ukraine's ambassador to the UN Sergiy Kyslytsya.

According to diplomats, non-permanent members of the Security Council Norway and Mexico submitted a text expressing "strong support to the efforts of the Secretary-General and the offer of his good offices in the search for a peaceful solution."

An adoption of the statement, which would be the first show of unity in the council since Russia's February 24 invasion, remains uncertain.

"There is time," Deputy Russian Ambassador Dmitry Polyanskiy told AFP when asked if Moscow might approve it.

Convoy to rescue civilians from 'bleak hell'

A new UN convoy was expected in Mariupol Friday to evacuate civilians from the "bleak hell" of a besieged steel plant that has become the last pocket of resistance against invading Russian forces in the southern port city.

The Russian military had announced a three-day ceasefire at the site starting Thursday but a Ukrainian commander said there was still heavy fighting at the sprawling Azovstal complex, where hundreds of soldiers and civilians have been holed up for weeks under heavy bombardment.

Ten weeks into a war that has killed thousands, destroyed cities and uprooted more than 13 million people, Russia has focused its efforts on Ukraine's east and south, and taking full control of the now-flattened Mariupol would be a major victory for Moscow.

"A convoy is proceeding to get to Azovstal by tomorrow morning hopefully to receive those civilians remaining in that bleak hell," UN humanitarian chief Martin Griffiths told a Ukraine donor conference in Warsaw on Thursday.

The mayor of Mariupol estimates around 200 civilians remain sheltering in dismal conditions in the plant's Soviet-era underground tunnels. 

"We still have to evacuate civilians from there, women and children. Just imagine... more than two months of constant bombing and constant death," Ukrainian President Volodymyr Zelensky said in his evening address on Thursday.

The International Committee of the Red Cross (ICRC) told AFP "that a safe passage operation is ongoing" in coordination with the UN. The two organisations have already worked together to evacuate some 100 civilians from the complex.

Speaking to the Israeli prime minister Thursday, Russian President Vladimir Putin said his military was ready to allow civilians to leave, according to the Kremlin.

"As for the militants remaining at Azovstal, the Kyiv authorities must give them an order to lay down their arms," Putin said.

A commander of the Azov regiment defending the factory said in a video on Telegram that there was still heavy bloody fighting.

"The Russians violated the promise of a truce and did not allow the evacuation of civilians who continue to hide from shelling in the basement of the plant," Svyatoslav Palamar said.

- Pentagon denial -

Since failing to take Kyiv early on in its invasion, which began February 24, Russia has focused its efforts on Ukraine's east and south.

Seizing the strategically located Mariupol would allow Moscow to create a land bridge between the separatist pro-Russian regions in eastern Ukraine and Crimea, which it annexed in 2014.

The Kremlin conceded Thursday that Kyiv's Western partners had prevented a quick end to Moscow's campaign by sharing intelligence and weapons with Ukraine, but that it was "incapable of hindering the achievement" of Russia's military operation.

The United States is among Ukraine's biggest backers, supplying military equipment and munitions worth billions of dollars as well as intelligence and training.

But the White House has sought to limit knowledge of the full extent of its assistance to avoid provoking Russia into a broader conflict beyond Ukraine.

Washington on Thursday denied an explosive report in The New York Times that it helped Ukraine target Russian generals.

"The United States provides battlefield intelligence to help the Ukrainians defend their country," National Security Council spokesperson Adrienne Watson said.

"We do not provide intelligence with the intent to kill Russian generals."

Separately, US media reported Thursday that Washington had shared intelligence that helped Ukraine sink the Russian warship Moskva last month.

However a US official, who spoke on condition of anonymity, told AFP that the United States does not "provide specific targeting information on ships." 

- Fiji seizes oligarch's yacht -

Ukraine's government has estimated at least $600 billion will be needed to rebuild the country after the war.

President Zelensky, who has tirelessly campaigned for help from allies, on Thursday launched a global crowdfunding platform called United24 to help Ukraine win the war and rebuild its infrastructure.

More than six billion euros ($6.3 billion) were collected at a donors' conference in Warsaw, Polish Prime Minister Mateusz Morawiecki said Thursday.

In addition to financial and military assistance, Ukraine's allies have also punished Russia for the invasion with unprecedented sanctions.

In one of the latest such moves, the British government said Thursday it had frozen the assets of UK-based steel and mining firm Evraz as it is of strategic significance for Russia's war effort.

Evraz's main shareholder is Russian oligarch Roman Abramovich, who is already under sanctions, and its main operations are in Russia.

And in another action against oligarchs close to Putin, authorities in Fiji seized the $300 million yacht of Suleiman Kerimov after the United States requested be held for sanctions violations and ties to corruption.

- Farmers on the front line -

Fighting continued across eastern Ukraine.

Donbas regional governor Pavlo Kyrylenko said at least 25 civilians were wounded in an overnight Russian strike on the city of Kramatorsk.

Elsewhere, the Ukrainian army said it had retaken control of "several settlements on the border of Mykolaiv and Kherson regions".

In the southwest, farmers racing to keep up with the spring planting season have found themselves ploughing around unexploded ordnance -- one more piece of worrying news for next year's harvest in Europe's breadbasket.

"Every day since the start of the war we have been finding and destroying unexploded ammunition," Dmytro Polishchuk, one of the deminers, told AFP before heading into a field in the southwestern village of Grygorivka to destroy an unexploded rocket.

Latest developments

Here are the latest developments in the war in Ukraine:

-Mariupol factory ceasefire in doubt -

The Russian military had announced a three-day ceasefire starting Thursday at the besieged Azovstal steelworks in the southern port city of Mariupol, where Ukrainian forces are making a last stand.

But a commander of the Azov regiment which is defending it says in a video on Telegram that "heavy bloody fighting continues", accusing Russia of violating its promise of a ceasefire.

President Vladimir Putin says the Russian army is "still ready" to give safe passage to civilians trapped at Azovstal.

"As for the militants remaining at Azovstal, the Kyiv authorities must give them an order to lay down their arms," the Kremlin quotes Putin as saying.

- West slowing, not hindering operation: Kremlin -

The Kremlin accuses the West of preventing a quick end to Russia's military campaign.

"The United States, Britain, NATO as a whole hand over intelligence... to Ukraine's armed forces on a permanent basis," spokesman Dmitry Peskov tells reporters. 

"Coupled with the flow of weapons that these countries are sending to Ukraine, these are all actions that do not contribute to the quick completion of the operation."

But Peskov says the West is "incapable of hindering the achievement" of the Russian operation's goals.

- Donor conference, crowdfunding -

More than six billion euros ($6.3 billion) were collected at a Ukraine donors' conference in Warsaw, Polish Prime Minister Mateusz Morawiecki says.

Separately, Ukrainian President Volodymyr Zelensky launches a global crowdfunding platform -- United24 -- to help Kyiv win the war with Russia and rebuild the country's infrastructure.

Ukraine's government in April estimated the cost of rebuilding after the war to be at least $600 billion (570 billion euros).

- Fiji seizes oligarch's yacht -

Authorities in Fiji seize the $300 million yacht of Russian oligarch Suleiman Kerimov after a US request to hold the vessel for violating sanctions and for alleged ties to corruption, the US Justice Department says.

The 348-foot (106-metre) "Amadea" was berthed in Lautoka, Fiji in the South Pacific when local authorities took control of it.

- Sell seized assets: EU chief -

The European Union should confiscate and sell Russian assets it has seized and use the proceeds to rebuild Ukraine, EU chief Charles Michel says, echoing an idea already floated in the United States. 

The EU said early last month it had frozen 30 billion euros ($31.5 billion) in assets linked to blacklisted Russian and Belarusian individuals.

- Eastern assault continues -

The governor of Ukraine's eastern Donbas region Pavlo Kyrylenko says at least 25 civilians were wounded in an overnight Russian strike on the city of Kramatorsk.

Moscow seeks to establish "full control" of the regions of Lugansk and Donetsk, and to maintain a land corridor to occupied Crimea.

The Ukrainian army meanwhile says it has retaken control of "several settlements on the border of Mykolaiv and Kherson regions". 

- Russia, Israel and the Holocaust -

Israeli Prime Minister Naftali Bennett says Putin has apologised for remarks made by Russian Foreign Minister Sergei Lavrov, who claimed Adolf Hitler may have had "Jewish blood". 

The comments had sparked outrage in Israel.

A Kremlin summary of the Bennett-Putin call, which came as Israel marked 74 years since the creation of the Jewish state, made no mention of a Putin apology.

It did, however, note that the leaders discussed the "historic memory" of the Holocaust.

- Zelensky invites German leaders -

German Chancellor Olaf Scholz is yet to commit to visiting Kyiv, even after Ukraine's leader invited him and President Frank-Walter Steinmeier -- three weeks after the German president was snubbed by Kyiv.

- NATO, Sweden and the Baltic Sea -

NATO Secretary General Jens Stoltenberg says the alliance could heighten its presence around Sweden and the Baltic Sea to protect the country from Russian interference during a potential membership application.