The US will send $53 million in aid, including $46 million in military assistance, to Ukraine’s military but declined a request from President Petro Poroshenko to send lethal aid to help in the battle against Russian-backed separatists.

While Poroshenko thanked the United States for the non-lethal equipment it is providing to his country’s beleaguered military, he said much more was needed to halt the advance of Russia-backed separatists.

“Blankets and night-vision goggles are important, but one cannot win a war with a blanket,” he said. Poroshenko was speaking during a 40-minute address to a joint meeting of Congress that was repeatedly interrupted by applause from lawmakers.

Poroshenko arrived at the White House later in the day for one-on-one discussions with US President Barack Obama, who said at the meeting that Poroshenko's leadership had been "critical, at a very, very important time in Ukraine's history".

"Unfortunately, what we have also seen is Russian aggression, first in Crimea and most recently in portions of eastern Ukraine," Obama said.