New York, New York - In a wide-ranging interview with Time Magazine, President-elect Donald Trump said he disagrees "very vehemently" with Ukraine firing US-supplied missiles deep into Russia.

Trump vowed he would not abandon Ukraine, as US support for Kyiv would be key leverage in fulfilling his promise to bring the war to an end.

Washington has supplied its long-range ATACMS missiles to Ukraine, which has used it to strike inside Russia, provoking angry retaliation from Moscow, including through the use of an experimental hypersonic missile.

"I disagree very vehemently with sending missiles hundreds of miles into Russia. Why are we doing that?" he told Time Magazine, which named him its Person of the Year on Thursday.

Donald Trump Village People issue official response to invitation to perform at Trump's inauguration

The interview was conducted before Thanksgiving and Trump's high-profile meeting with Ukrainian President Volodymyr Zelensky brokered by France's president on the sidelines of the reopening of Notre Dame cathedral.

"We're just escalating this war and making it worse. That should not have been allowed to be done," the incoming president said, calling the Biden administration's decision a "very big mistake."

Pressed on his support for Ukraine, which has been lukewarm at best, Trump said he would use previous backing as leverage to bring the war to a close.

"I want to reach an agreement and the only way you're going to reach an agreement is not to abandon," he insisted.

Russian news agencies have jumped on Trump's comments, drawing attention to the Republican's apparent criticism of Kyiv's approach.