The capital Kyiv remains under Ukrainian control as does Kharkiv in the east, with the overall picture of the 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 the sides, Western defence and intelligence sources and international organisations.

- The east

Kharkiv remains in Ukrainian hands despite intense bombardments, 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 and efforts underway to extract foreign students.

- Kyiv and the north

Kyiv remains under Ukrainian control, despite heavy bombardments, although Western observers have pointed to a major Russian column of hundreds of vehicles outside the city stationed around the Hostomel airfield.

There has been heavy fighting in the vicinity of Hostomel but the column has made little progress in recent days.

Ukrainian forces also retain control of the northern town of Chernihiv where there have been heavy civilian casualties in recent days.

- The south -

Russia has besieged the strategic southern city of Mariupol and the International Committee of the Red Cross said a new attempt to evacuate an estimated 200,000 civilians from the city had failed.

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

The famed port city Odessa remains in Ukrainian control and has been for now 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 the annexed Ukrainian peninsula 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 seeking to leave the country.

Zelensky said the civilian airport in the central city of Vinnytsia was completely destroyed by Russian rockets, in an area far from the limit of the Russian ground advance.

- 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 UN said Friday it had recorded nearly 331 killed a civilian deaths in Ukraine, although the true toll could be far higher.

- Refugees

Over 1.5 million refugees have fled Ukraine in the week since the invasion, with over half going to Poland, according to the UN refugee agency.