Former German Foreign Minister Guido Westerwelle has died following a battle with leukemia. He was 54.

Alexander Vogel, the head of Westerwelle's office at the Westerwelle Foundation, said he died on Friday. He did not give further details.

Westerwelle was Germany's foreign minister from 2009 to 2013 and Chancellor Angela Merkel's vice chancellor from 2009 until 2011.

As foreign minister, Westerwelle strongly advocated a "culture of military restraint" and opposed NATO's military intervention in Libya in 2011.

Westerwelle became foreign minister and vice chancellor in 2009 after leading his pro-business Free Democratic Party, post-war Germany's traditional kingmaker, to its best-ever election result and ending an 11-year spell in opposition.