On the 12th day of Russia's invasion of Ukraine Monday, Russian forces pressed a siege of the key southern port of Mariupol and sought to increase pressure on the capital Kyiv.

Kyiv remains under Ukrainian control as does Kharkiv in the east, with the overall Russian ground advance little changed over the last 24 hours in the face of fierce Ukrainian resistance.

Here is a summary of the situation on the ground, based on statements from both sides, Western defence and intelligence sources and international organisations.

The east 

Kharkiv remains in Ukrainian hands despite increasingly intense Russian bombardment and the city is surrounded, according to Western sources.

Russian forces are also pressing an offensive through the Russian-backed separatist Donetsk and Lugansk regions although how far they have penetrated remains unclear.

There has been heavy fighting around and inside the city of Sumy in northeast Ukraine, where Kyiv said there was intense Russian shelling.

Kyiv and the north 

Kyiv remains under Ukrainian control, despite heavy bombardments, although Western observers point to a major Russian column of hundreds of vehicles outside the city.

The front line is now just 20 kilometres (12 miles) outside the city, according to French sources.

There has been heavy fighting in the vicinity of Gostomel around where the column is located and the mayor of the town was killed by Russian forces, local authorities said.

Ukrainian forces also retain control of the northern town of Chernigiv, which has seen heavy civilian casualties in recent days.

Britain's defence ministry said Russia appeared to have made "minimal" progress on the ground over the weekend.

The south 

Russia has besieged the strategic southern city of Mariupol and attempts to evacuate an estimated 200,000 civilians from the city have so far failed. 

Taking the city would allow Russia to link forces pushing north from the annexed Ukrainian peninsula of Crimea with their forces from the east.

The famed port city Odessa remains under Ukrainian control and has been so far spared fighting. But Ukraine's President Volodymyr Zelensky said he was aware of intelligence that Russia planned to bomb the city.

Russian forces last week took the southern city of Kherson, just north of Crimea, and now appear to be moving on Mykolayiv to the northwest.

The west and centre 

The west of Ukraine remains largely spared from the fighting. The main western city of Lviv has become a hub for foreign diplomatic missions, journalists and Ukrainians seeking safety or wanting to leave the country.

Zelensky said Sunday the civilian airport in the central city of Vinnytsia was destroyed by Russian rockets. Rescue services said five civilians and four soldiers were killed.

Casualties 

Russia said Wednesday that 498 Russian troops had been killed in Ukraine, its first announced death toll.

Ukraine and Western sources claim that the real toll is far higher. Ukraine says around 11,000 Russian soldiers have been killed.

The United Nations said Thursday it had recorded 364 civilian deaths in Ukraine, including 25 children, although the true toll could be far higher.

Refugees 

Over 1.7 million refugees have fled Ukraine since the invasion, with over half going to Poland, according to the UN refugee agency.