US Vice President JD Vance will lead America's delegation to the Munich Security Conference that starts on Friday in the southern German city, where world leaders and diplomats are gathering amid intense concern and uncertainty over the Trump administration's foreign policy.

The future of Ukraine will be the top item on the agenda following a phone call between US President Donald Trump and Russian leader Vladimir Putin this week, when they pledged to work together to end the three-year-old Russia-Ukraine conflict .

Vance is expected to meet Ukrainian President Volodymyr Zelensky on Friday for talks that many — particularly in Europe — hope will shed at least some light on Trump’s ideas for a negotiated settlement to the war.

US Secretary of State Marco Rubio was supposed to join them but was delayed when his Air Force plane had to return to Washington after developing a mechanical problem en route to Munich.

The State Department said he would take a different aircraft, but it was unclear whether he would arrive in time for the meeting with Zelensky.

Trump, who upended years of steadfast US support for Ukraine during his call with Putin on Wednesday, has been vague about his specific intentions — other than suggesting that a deal will likely result in Ukraine being forced to cede territory that Russia has seized since it annexed Crimea in 2014.

“The Ukraine war has to end,” Trump told reporters Thursday. “Young people are being killed at levels that nobody’s seen since World War II. And it’s a ridiculous war.”

The Russia-Ukraine war is the biggest conflict on the European continent since World War II.

Foreign Minister Wang Yi will also be in Munich to communicate Beijing's position on global security.

On Ukraine, state media cited Wang as saying China welcomes all efforts committed to peace talks and supports building a "balanced, effective and sustainable European security architecture." (Agencies)