NATO chose stability on Thursday by extending Secretary-General Jens Stoltenberg's term in office for an extra year to help steer the 30-nation military alliance through the security crisis sparked by Russia-Ukraine conflict.

Stoltenberg tweeted Thursday that he is "honored" by the decision of NATO leaders to extend his term until September 30, 2023.

"As we face the biggest security crisis in a generation, we stand united to keep our alliance strong and our people safe," he said, after U.S. President Joe Biden and his counterparts agreed to extend his term at a summit in Brussels.

The former Norwegian prime minister was named to NATO's top civilian post in October 2014. It's the second time that his term of office has been extended. His mandate was due to expire in September.

In a tweet, Biden said that Stoltenberg has "done a remarkable job leading and strengthening our Alliance — particularly during this critical moment for international security.”

In February, Norway's government appointed Stoltenberg as head of the Scandinavian country's central bank and said it hoped he could start in his new role around December 1.

In Oslo, Finance Minister Trygve Slagsvold Vedum confirmed that Stoltenberg had resigned from the job. Temporary governor Ida Wolden Bache has been nominated in his place and her appointment is expected to be confirmed later Thursday.

"Of course I would like to see Jens Stoltenberg become our next central bank governor, but we are in the middle of a dramatic situation in Europe and I have great understanding that he prioritizes continuing in the important role he has in NATO," Slagsvold Vedum said.

Stoltenberg, 63, was twice prime minister in Norway and he also served as finance minister, and industry and energy minister.

Prior to Thursday's announcement, speculation had been rife that a woman would be named at the helm of the world's biggest security organization for the first time.