German President Horst Koehler addresses the media at the presidential residence Bellevue palace in Berlin May 31, 2010. [Agencies]

BERLIN - German Federal President Horst Koehler announced Monday that he will step down with immediate effect for criticism of his controversial remarks on German troops' mission in Afghanistan.

"I declare my resignation from the office of President," said Koehler in Berlin.

Kohler said he has informed Jens Boehrnsen, president of the upper house of the German parliament, on his resignation. Boehrnsen will temporarily assume the presidential duty.

Kohler has triggered an outcry with a statement that military operations could also serve the economic interests of Germany. He said later that he had been misunderstood and that his remarks did not refer to the Afghanistan mission but rather to occasions such as military missions against pirates.