Leaders from around the world are arriving in Munich for the Munich Security Conference, which runs until Sunday, DPA reported.
The high-level talks will focus mainly on Ukraine, where the war will enter its fifth year later this month, and Iran, which Trump has warned could be subject to military strikes if a nuclear deal is not reached soon.
But just over a year into Trump's second term, the deepening rift between the United States and Europe is also expected to take center stage in the debates.
The annual Munich Security Report set a somber tone ahead of the event, branding Trump a “disruptor” on the international order since 1945.
German Chancellor Friedrich Merz will open the conference, considered the leading forum for discussions on security and defense issues. It will be the conservative leader's first appearance at the conference as chancellor.
US Vice President J.D. Vance, who shocked last year's Munich audience with his scathing criticism of European leaders, accusing them of suppressing free speech and ignoring the opinions of right-wing voters, will not be attending this year. US Secretary of State Marco Rubio is scheduled to speak in his place on Saturday morning.
The question of whether the US remains committed to European security and NATO is expected to dominate both the panel discussions and the closed-door meetings.
Organizers of the forum said more than 60 world leaders would attend, more than ever before. About 100 foreign and defense ministers will also participate.