US President-elect Donald Trump says he is going to meet Russian President Vladimir Putin "very quickly" after he takes office next week.

He did not provide a timeline for the meeting, which would be the first between the leaders of the two countries since Russia's war with Ukraine started in February 2022.

When asked about his strategy to end the war, Trump told Newsmax: "Well, there's only one strategy and it's up to Putin and I can't imagine he's too thrilled about the way it's gone because it hasn't gone exactly well for him either.

"And I know he wants to meet and I'm going to meet very quickly. I would've done it sooner but ... you have to get into the office. For some of the things, you do have to be there."

US Congressman Mike Waltz, the incoming national security adviser, said on Sunday he expected a call between Trump and Putin in "the coming days and weeks".

Russia's invasion of Ukraine has left tens of thousands of people dead, displaced millions and triggered the biggest rupture in relations between Moscow and the West since the 1962 Cuban Missile Crisis.

Trump's return to the White House on January 20 has sparked hope of a diplomatic resolution to end Moscow's invasion of Ukraine, but it has also led to fears in Kyiv that a quick peace deal could come at a high price for Ukraine.

Advisers to Trump have floated proposals to end the war that would effectively cede large parts of the country to Russia for the foreseeable future.

"He wants to meet, and we are setting it up," Trump said last week in remarks before a meeting with Republican governors at Mar-a-Lago in Palm Beach, Florida.

"President Putin wants to meet. He has said that even publicly and we have to get that war over with."

Since the Russian invasion began, the United States under Democratic President Joe Biden has committed over $175 billion in aid for Ukraine, including over $60 billion in security assistance.

However, it is uncertain if the aid will continue at that pace under Trump, who has said he wants to bring the war to a swift end.

Kremlin spokesman Dmitry Peskov recently said Putin would welcome Trump's desire for contact, but so far there have been no formal requests. It would be more appropriate to wait for Trump to take office first, Peskov said.

Peskov said Putin had repeatedly stated his willingness to hold talks with international leaders, including Trump.

"We see that Mr Trump also declares his readiness to resolve problems through dialogue, we welcome this."

While speaking positively of Trump, Peskov was highly critical of outgoing President Joe Biden.

He said the Biden administration, in its final 10 days, "intends to continue doing everything to continue the war", including possible new sanctions against Russia.

"We are aware that the administration will certainly try to leave the most burdensome legacy in terms of bilateral relations for the incoming Trump and his associates," said Peskov.

Ukrainian President Volodymyr Zelensky has said Trump could be decisive in the outcome of the 34-month-old war with Russia and help stop Putin.