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.

After years in which Germany's Chancellor Olaf Scholz has been accused of treading lightly on European and world stages, conservative election front-runner Friedrich Merz has vowed a bold return to international affairs.