Ukranian President Volodymyr Zelenskiy has told a US military audience he hopes he can still count on the United States and urged Congress not play into Russian President Vladimir Putin's hands, as he started a critical visit to Washington to shore up security assistance.
"We won't give up. We know what to do and you can count on Ukraine. And we hope just as much to be able to count on you," Zelenskiy said in an address to the National Defense University on Monday.
US President Joe Biden's administration has warned Congress that a failure to renew military assistance to Ukraine could tip the nearly two-year-old war in Russia's favour, creating national security threats for the West.
Zelenskiy, in an oblique reference to disputes in Congress over allocating aid, said it was "crucial that politics ... not betray the soldiers".
"Let me be frank with you, friends. If there's anyone inspired by unresolved issues on Capital Hill, it's just Putin and his sick clique," Zelenskiy added.
Zelenskiy has been invited to meetings at the White House and with members of Congress on Tuesday. Many Republican lawmakers have questioned continued aid to Ukraine.
Russian President Vladimir Putin launched his invasion of Ukraine early last year, triggering a war that has killed or wounded hundreds of thousands and led to the biggest confrontation between Russia and the West in six decades.
Bolstered by billions of US military aid, as well as US intelligence, Ukraine was able to fend off Russia's initial attempt to sweep the country and roll Russian forces back in key towns.
But Kyiv failed to break through Russian defensive lines in a major counteroffensive push this year and Russia is now on the offensive in the east.
US Defense Secretary Lloyd Austin warned that Putin still hoped to achieve victory in Ukraine, even as he offered assurances of "unshakable" US support to the country.
"Despite his crimes and despite his isolation, Putin still believes that he can outlast Ukraine and that he can outlast America. But he is wrong," Austin said to applause.
He added, in apparent reference to Congress: "America's commitments must be honoured."
Congress has approved more than $110 billion for Ukraine since Russia's February 2022 invasion but it has not approved any funds since Republicans took over the House from Democrats in January.
By mid-November, the US Defense Department had used 97 per cent of $62.3 billion in supplemental funding and the State Department had used all of the $4.7 billion in military assistance funding for Ukraine it had been allocated, US budget director Shalanda Young said last week.
Australian Associated Press