The Ukrainian president said civilians and military alike would protect the country's independence, while Kyiv's mayor said the city was entering a "defensive phase"
The centre of Kyiv remained in Ukrainian hands in the early hours of Saturday morning as intense fighting overnight appeared to stem the advance of Russia's military towards the city.
Explosions and gunfire were heard throughout the night around the Ukrainian city, with reports of hundreds of casulaties in the fighting.
The shelling sliced through at least one Kyiv apartment building and pummelled bridges and schools.
Ukraine's president Volodymyr Zelenskyy refused a U.S. offer to help him leave the city amid growing signs that Russia wanted to overthrow his government.
Meanwhile the U.S. joined other Western allies in imposing sanctions directly on Russian President Vladimir Putin and his foreign minister, Sergei Lavrov.
Follow all of Friday's developments in our live blog below: