German opposition leader Friedrich Merz, tipped to become the next chancellor, said on Thursday he wanted to win back the lost trust of key allies and ensure Berlin is more assertive on the global stage in a speech laying out his foreign policy plans.

The conservative leader wants to impose strict border controls after knife killings in Aschaffenburg this week.

Friedrich Merz, a top candidate for German chancellor, criticized a leaked briefing by Germany's U.S. ambassador that condemned Trump's policies. The briefing, reported by Reuters, challenges Trump's democratic principles and media independence.