"If there's interest, I would be ready and I think I have experience and certain qualities and skills that I could bring to the table," Karins, a former prime minister of his country, said after a NATO meeting in Brussels.

He insisted he was not yet an "official candidate" being proposed by Latvia's government.

Stoltenberg -- who has had his tenure extended twice in the face of Russia's war on Ukraine -- is expected to leave when his current term ends next autumn.

Outgoing Dutch Prime Minister Mark Rutte has put himself forward and is seen as a clear front-runner by diplomats with backing from heavyweights including France and Germany.

Karins said he "can only speak well" of Rutte -- who would become the fourth Dutchman to head the alliance -- after working with him on the European stage for years.

But the Baltic leader said NATO should look beyond the small group of core countries for a next boss and turn its eyes to newer members closer to the Russian threat in the east.

Another potential name in the running for the job is Prime Minister Kaja Kallas from Latvia's neighbour Estonia.

"What's important is that in this process, we look throughout the entire alliance at potential candidates," Karins said.

"It is no longer a small alliance fighting a Cold War. It is now a very broad alliance, 31 countries soon to be 32, which spans basically the entire continent."

Latvia's top diplomat -- who was born in US President Joe Biden's hometown of Wilmington, Delaware -- said it would send a "good signal" if the next NATO chief came from a country that reached the alliance's two-percent target on defence spending.

"For the believability of the secretary general, if that individual comes from a country which meets that there's no one can say: 'Well, wait a minute, your country's not doing it'."

Latvia's military spending this year reached 2.25 percent of gross domestic product and is set to hit 2.5 in 2025.

Rutte has not managed to get the Netherlands beyond the two-percent target during his 13 years in charge, but his government has pledged the country will reach it next year.