Berlin, Feb 2 (IANS): Former German President Horst Koehler passed away at the age of 81 after an illness, according to the Office of the Federal President of Germany.

Koehler, being German president from July 2004 to May 2010, unexpectedly resigned from the post following criticism of his comments concerning the overseas operations of Germany's armed forces, Xinhua news agency reported.

German President Frank-Walter Steinmeier expressed his condolences to Eva Luise Koehler on Saturday regarding her husband's death and appreciated Koehler's service and contributions to the country.

Before becoming president Horst Koehler was the head of the IMF in Washington from 2000 to 2004, and also held other roles in the civil service and banking.

He became Germany's head of state, a mostly ceremonial role, after being put forward by then opposition leader Angela Merkel, who went on to become chancellor.

Steinmeier said that when he was elected, the member of the centre-right CDU party was "virtually unknown".

He was re-elected for a second term in 2009, but in May of the following year, he shocked the nation by resigning unexpectedly. His decision came after controversial remarks in an interview where he seemed to connect Germany's military presence in Afghanistan with protecting economic interests.

These comments stirred significant debate, given the lingering sensitivity in Germany regarding military operations abroad, a sentiment shaped by the painful memories of the Nazi era.

Throughout his speeches, Koehler often stressed the importance of having confidence in Germany's strength and the vitality and creativity of its people.