Trump call with Putin expected soon: Trump adviser

US President-elect Donald Trump and Russian President Vladimir Putin are expected to have a call in the coming days or weeks, and it is unrealistic to aim to expel Russian soldiers from every inch of Ukrainian territory, a top Trump adviser said.

Trump, who will return as US president on Jan. 20, styles himself as a master dealmaker and has vowed to swiftly end the war in Ukraine but not set out how he might achieve that.

US Congressman Mike Waltz, the incoming national security adviser, told ABC on Sunday that the war had become a World War One-style "meat grinder of people and resources" with "World War Three consequences", according to ABC.

"Everybody knows that this has to end somehow diplomatically," Waltz, a Trump loyalist who also served in the National Guard as a colonel, told ABC.

"I just don't think it's realistic to say we're going to expel every Russian from every inch of Ukrainian soil, even Crimea. President Trump has acknowledged that reality, and I think it's been a huge step forward that the entire world is acknowledging that reality. Now let's move forward."

Asked specifically about contacts between Trump and Putin, Waltz said: "I do expect a call for, at least in the coming days and weeks. So, that would be a step and we'll take it from there."

Russia's 2022 invasion of Ukraine has left tens of thousands dead, displaced millions of people and triggered the biggest rupture in relations between Moscow and the West since the 1962 Cuban Missile Crisis.

US officials cast Russia as a corrupt autocracy that is the biggest nation-state threat to the United States and has meddled in US elections, jailed US citizens on false charges and perpetrated sabotage campaigns against US allies.

Russian officials say the US is a declining power that has repeatedly ignored Russia's interests since the 1991 break-up of the Soviet Union, and that sowing discord inside Russia is an attempt to divide Russian society and further US interests.