Ukrainian President Volodymyr Zelensky has urged European countries to do more to help as he urged his citizens to resist Russian invasion.
The second day of fighting saw tanks enter the capital, Kyiv, for the first time.
Ukrainian officials said they have handed out 18,000 guns to volunteers, as well as issuing instructions on how to make petrol bombs.
Russia is continuing its assault from the north, south and east.
Loud explosions have been reported in the second-largest city, Kharkiv in the north-east, with Ukrainians saying they have stalled a Russian advance
Mariupol, a strategically important port city on the Sea of Azov to the south, is reportedly under attack
A group of 13 soldiers on Zmiinyi (Snake) island are being honoured as heroes after they died refusing to surrender to a Russian warship
Ukraine says at least 137 people – civilians and soldiers – have been killed, while Russia has not admitted any deaths on its side
More than 100,000 people are estimated to have fled their homes, heading to family or fleeing for the border.
“Russian tanks are still shooting residential buildings in our cities,” Mr Zelensky said in an address to the nation earlier.
The US, UK and EU have all levied financial punishment on Moscow, but stopped short of removing Russia from the international banking system, Swift.
However, Mr Zelensky said Western nations – and nearby Europe in particular – must go further and “act without delay”.
He said “Europe has enough strength to stop this aggression,” .
“The columns of tanks and the air strikes are very similar to what Europe saw a long time ago, during WW2 – something about which it said ‘never again’,” he said. “But here it is, again. Now, in 2022. 75 years after World War Two ended.”
He said all counter-measures must be considered – including throwing Russia out of Swift, imposing visa bans and closing airspace to Russia.
The Ukrainian president’s appeal came as Russia offered talks with Ukraine for the first time since the crisis began, but under restrictive conditions. Mr Zelensky has been seeking talks with Vladimir Putin since before the invasion began.
Kremlin spokesman Dmitry Peskov said Russia was prepared for talks with Ukraine, but only in the context of “demilitarisation” and about Ukraine’s “neutral status”.
Russia has said that Ukraine can never be allowed to join the Nato military alliance, a long-held ambition of Ukraine’s.
Russia’s Foreign Minister, Sergei Lavrov, said earlier that no talks could take place until Ukraine’s military laid down its arms.
But President Zelensky has given no indication that he would accept talks under those conditions.
Addressing the armed forces, Mr Zelensky said: “Stand strong. You are all that we have. You are all that is protecting our state.”
Editing by Omotola Oguneye