German President Horst Koehler has resigned in a surprise move after being criticised for reportedly linking military deployments abroad with the country's economic interests - creating a new headache for Chancellor Angela Merkel.
The resignation, effective immediately, came only a year into Mr Koehler's second term as the largely ceremonial head of state. Ms Merkel had installed the former International Monetary Fund boss as president in 2004.
The current president of parliament's upper house - Bremen Mayor Jens Boehrnsen, a member of the opposition Social Democrats - will take over presidential duties temporarily, largely signing legislation into law.
A new president must be elected within 30 days. German politicians will have to figure out quickly who should replace Mr Koehler even as they are preoccupied with trying to make budget cuts amid the eurozone debt crisis.
Ms Merkel called off a planned visit to the German World Cup team's training camp in Italy.
Mr Koehler, a member of Ms Merkel's Christian Democrats, cited a week of criticism over a radio interview he gave following a visit to German troops in Afghanistan.
He said in that broadcast that, for a country with Germany's dependency on exports, military deployments could be "necessary... in order to defend our interests, for example free trade routes".
That was taken by many as relating to Germany's unpopular mission in Afghanistan, although his office later said that he was referring to anti-piracy patrols off the coast of Somalia. Germans are often uneasy about deployments abroad, given the country's militaristic past, and the mission in Afghanistan makes many particularly uncomfortable.
Opposition politicians had called for Mr Koehler to take back the remarks and accused him of damaging public acceptance of German military missions abroad.
"I regret that my comments in an important and difficult question for our nation were able to lead to misunderstandings," a strained-looking Mr Koehler told reporters at the president's Bellevue palace.