The Euroskeptic Center Party quit the two-party coalition last week, leaving Prime Minister Jonas Gahr Støre’s center-left Labor Party to govern on its own.
Stoltenberg will replace the outgoing finance minister Trygve Slagsvold Vedum, from the Center Party.
Before becoming NATO chief, Stoltenberg served twice as Norway’s prime minister, 2000-2001 and 2005-2013. He also held the finance minister position in the 1990s.
In his secretary-general role, Stoltenberg steered NATO through the tumultuous first administration of United States President Donald Trump from 2017 to 2021, earning the moniker “Trump whisperer” for convincing the U.S. president not to pull out of the transatlantic military alliance.
Stoltenberg will return to his position at the helm of the Munich Security Conference after he leaves public office, he added in his statement.
