Ukrainian President Volodymyr Zelensky has claimed the morale of Russian forces is crumbling.
UK Prime Minister Boris Johnson told MPs earlier that if President Vladimir Putin “doubles down, then so shall we”.
Russia wants to declare former Ukrainian president Viktor Yanukovych - ousted during anti-government protests in 2013-14 - as the new leader of Ukraine, the Ukrayinska Pravda news and analysis website has reported, quoting Ukrainian intelligence.
US President Joe Biden has told Congress that Vladimir Putin badly misjudged how the West would hit back once he invaded Ukraine.
Ukrainian emergency services say five people were killed in the Russian attack on the Kyiv television tower.
We've got an updated figure on the number of people who have fled Ukraine since Russia's invasion six days ago.
Ukraine's president has described the bombardment of Kharkiv, which has killed dozens of civilians, as a war crime.
Russia has moved from having 40% of its forces inside Ukraine to around 75%, a military academic says.
Dramatic satellite images released by Maxar Technologies on Monday evening showed a massive 40+ mile long convoy of Russian military vehicles snaking along roadways northwest of Kyiv.
New satellite images from Maxar Technologies show the Russian military convoy that has reached the outskirts of Kyiv is even longer than it previously measured.
Russia's unmanned Luna-25 spacecraft has crashed into the Moon after spinning out of control, officials say.
Donald Trump has confirmed that he will not take part in Republican presidential debates with his rivals in the race for the White House.