Here are the latest developments in Russia's war in Ukraine:

- US cool on Polish jets for Ukraine -

Poland is "ready" to hand its MiG-29 fighter jets to the United States, the foreign ministry says, under a scheme that would see the planes given to Ukraine.

But Washington rejects the offer as not "tenable", saying it raises "serious concerns" for the entire NATO alliance.

Washington says any decision to transfer Polish-owned planes to Ukraine is "ultimately one for the Polish government".

- US bans Russian oil -

President Joe Biden announces a ban on US imports of Russian oil, gas and coal, saying Ukraine will "never be a victory for Putin".

Britain also says it will phase out Russian oil imports by the end of this year, and the European Union says it will slash gas imports by two-thirds.

Crude prices surge on the US move, with the benchmark Brent jumping 6.8 percent.

Norway -- Europe's largest gas supplier after Russia -- says it cannot increase gas deliveries because its fields are already operating at full capacity.

- IAEA concerns on Chernobyl -

The UN's nuclear watchdog warns that the Chernobyl nuclear power plant is no longer transmitting data and voices concern for staff working under Russian guard at the Ukrainian site.

More than 200 technical staff and guards remain trapped there and have worked 13 days straight since the Russian takeover. 

IAEA chief Rafael Mariano Grossi reiterates an offer to travel to Chernobyl or elsewhere to ensure the safety of Ukraine's nuclear sites.

At the Zaporizhzhia  nuclear plant, Russian forces say in a video carried by Russian media that they have full control of the site and it is functioning normally. They accuse Ukraine of storing weapons at the facility.

- Thousands evacuated -

Ukraine evacuates 5,000 civilians from the northeastern city of Sumy under a deal with Moscow to hold fire and set up humanitarian corridors in cities besieged by Russian forces.

Convoys ferry the evacuees to the city of Lokhvytsia, around 150 kilometres (93 miles) to the southwest in Ukrainian-held territory.

Ukrainian authorities say 21 people, including two children, were killed in air strikes on the town on Monday.

Kyiv and its Western allies had rejected a previous proposal to evacuate Ukrainians to Russia and Belarus.

Attempts to evacuate civilians from the besieged city of Mariupol fail again, with Ukraine accusing Russia of attacking a humanitarian corridor.

- New ceasefire -

Moscow announces a new humanitarian ceasefire in Ukraine for Wednesday morning to allow civilians to flee.

Russia proposes to agree the routes and start time with Ukraine "before 03:00 MSK on March 9", Russian news agencies report.

- Zelensky defiant -

Ukraine's President Volodymyr Zelensky, invoking the wartime defiance of British prime minister Winston Churchill, vows to "fight to the end" in a historic virtual speech to UK lawmakers.

In an interview, he says he is no longer pressing for NATO membership for Ukraine, one of the main bones of contention with Moscow.

- Nord Stream 2 'dead', US says -

The controversial Nord Stream 2 pipeline that was halted over Russia's invasion is "dead", a senior US official says, appearing to dash any hopes that the $12-billion gas venture could have a future.

Sanctions against Moscow have piled up, with private firms also leaving the country or halting operations.

Fast-food giant McDonald's, Coca-Cola and coffee chain Starbucks become the latest firms to suspend operations in Russia.

- Putin 'angry and frustrated': US intel -

US intelligence chiefs brand Russia's Vladimir Putin "angry and frustrated", warning he is likely to "double down and try to grind down the Ukrainian military with no regard for civilian casualties".

Earlier, the Pentagon says it estimates between 2,000 and 4,000 Russian soldiers have been killed in the nearly two-week-old invasion. Russia has not given an update since March 2 when it announced 498 troops had been killed.

- Russia default 'imminent': Fitch -

Ratings agency Fitch downgrades Russia's sovereign debt rating further, saying the decision reflects the view that a default is "imminent".

If Russia were to default on a debt payment, it would be the first time since 1998.

- Two million refugees -

The UN says the number of people fleeing the war now tops two million.

Poland alone has received 1.2 million people.