Ukrainian President Volodymyr Zelensky has arrived in Washington DC to try to rescue an imperilled US defence package to Kyiv worth billions of dollars.
The aid has become embroiled in US domestic, partisan politics, with Republicans demanding concessions on border funding in exchange.
It marks Mr Zelensky’s third visit to the US since Russia’s 2022 invasion.
The week is a crucial one for Ukraine, with the EU also deciding whether to open accession talks to the bloc.
Hungarian Prime Minister Viktor Orban has signalled that he opposes the move, and has the power to block such a decision.
Mr Orban and Mr Zelensky had an apparently intense conversation when they met on Sunday at the inauguration of Argentina’s new president. The details of their discussion have not been revealed.
The Ukrainian president will arrive in Washington on Monday. As well as holding meetings with US President Joe Biden and Republican House Speaker Mike Johnson, he will address the Senate on Tuesday morning.
The White House said in a statement on Sunday that Mr Zelensky’s visit was meant “to underscore the United States’ unshakeable commitment to supporting the people of Ukraine as they defend themselves against Russia’s brutal invasion”.
The US military aid package, worth $60bn (£47.9bn; €55bn), is currently stalled in Congress, facing pushback from Republicans who argue that more money should be going to domestic security at the US-Mexico border.
A vote in the Senate last week saw a package, which included the funding but no border measures, blocked by Republicans.
In addition to more funds for border enforcement, Republicans are seeking reforms to the way in which undocumented migrants seeking political asylum in the US are processed.
“We’ve got to be able to have a change in policy on this,” Senator James Lankford of Oklahoma, one of the lead Republican negotiators, said in an interview on Sunday.
“All we’re trying to do is to say what tools are needed to be able to get this back in control, so we don’t have the chaos on our southern border.”
Mr Lankford said that Americans don’t want US national security on the border to be ignored while Congress focuses on Ukraine’s interests.
Although the Biden administration has expressed a willingness to accept some asylum policy changes, such concessions risk angering liberal lawmakers and further dividing a party that has already been fractured by the president’s support of Israel in the Gaza War. —BBC