Feb. 13 (UPI) -- U.S. Secretary of State Marco Rubio warned the old world had been replaced with a new era in geopolitics that would require fresh thinking and for respective nations to reassess their roles.

Speaking Thursday before departing Washington at the head of a U.S. delegation to the Munich Security Conference, the first big trans-Atlantic gathering since President Donald Trump threatened to annex Greenland, Rubio vowed to be honest with European allies about the United States' priorities.

"I think they want -- honestly, they want to know where we're going, where we'd like to go, where we'd like to go with them... I think it's at a defining moment. The world is changing very fast right in front of us. The old world is gone -- frankly, the world that I grew up in -- and we live in a new era in geopolitics, and it's going to require all of us to sort of reexamine what that looks like and what our role is going to be," said Rubio.

"We've had many of these conversations in private with many of our allies, and they are our allies, and we need to continue to have those conversations. And I think Saturday, hopefully, and the meetings we'll have there will move us in that direction," he added.