US President-elect Donald Trump's transition team announced that the Republican operative who outlined the potential contours of a US-backed Ukraine peace plan was not speaking on behalf of the president-elect.

Brian Lanza, a longtime Republican Party strategist, told the BBC that the Trump administration would ask Ukrainian President Volodymyr Zelensky for a "realistic vision for peace."

He stated that the priority of the new US administration in Ukraine will be the establishment of peace, not the return of lost Ukrainian territory, including Crimea. "If President Zelensky comes to the table and says that we can have peace only if we return Crimea, he will show us that he is not serious. "Crimea is lost," he said.

A spokesman for Trump's transition team denied that Lanza was speaking for Trump. His transition team is currently reviewing candidates for administration positions and developing policies that Trump could adopt during his second term.

- Brian Lanza was the contractor of the campaign - said the anonymous spokesman. "He does not work or speak for President Trump - he added.

During the campaign, Trump said he would find a solution to end the war "within a day" but did not explain how he would do it.

According to media reports, Zelensky and Trump spoke by phone this week, after the US elections, and Trump's supporter, billionaire Elon Musk, was included in the conversation. Trump has previously refused to rule out the possibility of ceding Ukrainian territory to Russia and has been vague in his statements about the conflict.

Some of his prominent allies have floated peace proposals that would effectively result in long-term Russian control of areas internationally recognized as Ukrainian territory.

Russia annexed the Crimean peninsula in 2014. More than two and a half years after launching an all-out invasion of Ukraine, Russian forces control just under 20 percent of Ukrainian territory. Zelensky has repeatedly stated that peace cannot be established as long as Russian forces are present in Ukraine and until they return all territory currently under Russian control, including Crimea.

His "victory plan," unveiled last month, includes that demand as well as a call for Ukraine to join NATO, which Russia opposes. Russian President Vladimir Putin said in June that the terms of peace talks included Ukraine giving up four regions annexed by Moscow, although it does not fully control them.