By Humeyra Pamuk

WASHINGTON (Reuters) -U.S. President Joe Biden will discuss top domestic and foreign policy priorities with President-elect Donald Trump when the two meet on Wednesday, and lobby the incoming administration not to abandon Ukraine, national security adviser Jake Sullivan said on Sunday.

Republican Trump will take office on Jan. 20 after defeating Vice President Kamala Harris in the Nov. 5 presidential election. Biden invited Trump to come to the Oval Office on Wednesday, the White House said.

In an interview on CBS’s “Face the Nation” show, Sullivan said Biden’s top message will be his commitment to ensure a peaceful transfer of power, and he will also talk to Trump about what’s happening in Europe, in Asia and the Middle East.

“The President will have the chance to explain to President Trump how he sees things, where they stand, and talk to President Trump about how President Trump is thinking about taking on these issues when he takes office,” Sullivan said.

A key topic will likely be Ukraine’s war with Russia, which Trump has pledged to end swiftly although he did not say how.

“President Biden will have the opportunity over the next 70 days to make the case to the Congress and to the incoming administration that the United States should not walk away from Ukraine, that walking away from Ukraine means more instability in Europe,” Sullivan said.

When asked if that means Biden will ask Congress to pass legislation to authorize more funding for Ukraine, Sullivan deferred.

“I’m not here to put forward a specific legislative proposal. President Biden will make the case that we do need ongoing resources for Ukraine beyond the end of his term,” Sullivan said.

Washington has provided tens of billions of dollars worth of U.S. military and economic aid to Ukraine since it was invaded by Russia in February of 2022, funding that Trump has repeatedly criticized and rallied against with other Republican lawmakers.

Trump insisted last year that Russian President Vladimir Putin never would have invaded Ukraine if he had been in the White House at the time. He told Reuters Ukraine may have to cede territory to reach a peace agreement, something the Ukrainians reject and Biden has never suggested.