Ukraine needs more weapons and heavy artillery to repel Russia's invasion, with Kyiv's top diplomat in Australia rejecting any prospect of a peace deal.
Ukraine ambassador Vasyl Myroshnychenko says Russian troops have been committing war crimes and Ukrainians will never forgive or forget the invasion.
"I get a message about the group of kids who were evacuated from Irpin. Their parents were killed, kids were raped, tortured. The oldest one is 14 and the others are even younger," he told Sky News.
"I don't see any prospect of a peace deal in the foreseeable future - I think we need to keep on fighting."
Mr Myroshnychenko echoed his president's call to strip Russia of its permanent member status within the United Nations Security Council, saying President Vladimir Putin had brought the country back to the Soviet era.
"There is no opposition in Russia, there is nobody there to oppose him," the ambassador said.
"(Putin) is taking Russia to those last days of the Soviet Union when it was collapsing. He's done so much damage for the country and I don't know when Russia will be able to repair that reputation."
The Czech Republic confirmed it would supply Ukraine with tanks and armoured personnel vehicles while Australia is preparing to send over its own Bushmasters to boost the country's defence effort.
The exact number of Bushmasters Australia is sending via its C-17 planes is due to be announced shortly.
The United States and its allies are also preparing further sanctions in response to the revelations of war crimes in Ukraine's north.
Russia has denied targeting civilians during its retreat from towns like Bucha, but Ukrainian officials say between 150 and 300 bodies lay in a single mass grave by a church in the town.
The White House says it will unveil new sanctions against Russian banks, officials and investment on Wednesday alongside the G7 and European Union, in part due to the war crimes uncovered in Bucha.
Mr Myroshnychenko said the resilience in his country was very high after eight years of Russia waging war against Ukraine, starting when it annexed Crimea in 2014.
"We are protecting our democracy, our freedom, and our choice to pursue European integration," he said.
"That's what Ukrainian people want. All the Russian speakers, Ukrainian speakers, Orthodox, Catholics, Jews and Muslims are united in fighting the Russian enemy."
with Reuters
