Russian advances across Ukraine have slowed in recent days amid mounting casualties, but attempts to encircle and cut off the capital Kyiv continue.
Here are the latest developments on day 21 of the invasion:
- Kyiv‘s suburbs saw some heavy aerial bombardment overnight
- Russian naval forces are gathering on the Black Sea near Odesa
- But supporting troops around Mykolaiv remain bogged down
- Siege of Mariupol continues after 20,000 were evacuated
Russia launched its attack in the early hours of 24 February, with its troops advancing from three main directions:
- Crimea in the south, which Russia annexed in 2014
- The Donetsk and Luhansk regions in the east, where Russian-backed separatists already controlled large areas of territory
- Belarus in the north, where Russian forces were taking part in joint military training exercises
The fight for Kyiv in the north
Russian troops have pushed towards Kyiv from the north, with the main advance coming down the west side of the Dnieper River via Chernobyl.
But those troops have faced serious logistical problems, with many vehicles running out of fuel, and have faced strong Ukrainian resistance along the way.
The closest Russian troops to the north west of Kyiv are in the suburbs of Bucha and Irpin, about 25km (15 miles) from the city centre, but they have failed to cross the Irpin River so far.
That river and others across the city, as well as difficult terrain like marshlands and bogs, have helped Ukrainian forces slow Russian advances so far.
A Russian advance towards the east of the capital has stalled around the suburb of Brovary, about 20km (12 miles) away from the centre of Kyiv.
Ukrainian generals in the capital have said their focus at the moment is on keeping Russian artillery out of range of the city centre.
Russian forces are attempting to encircle and cut off the capital, but large areas around the city remain under Ukrainian control, especially in the south.
Justin Bronk, a defence analyst at the Royal United Services Institute, told the BBC that he doubts Russia has enough ground forces in place to take Kyiv at the moment.
Big Russian gains in the south
Russian forces have made rapid gains across the south of the country, advancing east and west from Crimea.
In the south east, civilians remain trapped in Mariupol, a port city of about half a million people, which is encircled by Russian forces and has come under heavy fire.
So far, Ukrainian forces have managed to fend off Russian attempts on the ground to capture the city.
Elsewhere in the south, Russian advances on Mykolaiv in the west have slowed. Taking the city is key for the Russians to push further west towards Odesa.
Russian naval forces off the coast of Odesa have conducted some shelling of the city in recent days but an amphibious landing would be very difficult and a sign of Russian desperation, according to Mr Bronk.
Odesa is strategically important for Russia as it would cut off Ukraine’s access to the Black Sea.
Russian advances in the east
Fighting continues in the Donetsk and Luhansk regions, where Russian-backed separatists held significant territory before the Russian invasion.
In the north east, Russian troops have surrounded the city of Sumy, bombed vital infrastructure and cut off supply routes.
A similar attempt to encircle Kharkiv, Ukraine’s second-largest city, has been less successful with analysts suggesting Russian forces there are in short supply of ammunition.
Artillery attacks on residential areas of Kharkiv are being investigated by United Nations (UN) prosecutors for possible war crimes.
