NATO has appointed outgoing Dutch Prime Minister Mark Rutte to succeed Jens Stoltenberg in October as the alliance's next secretary general.
Welcoming the selection of Rutte, Stoltenberg said Rutte was "a true trans-Atlanticist, a strong leader, and a consensus-builder."
"I wish him every success as we continue to strengthen NATO for the challenges of today and tomorrow. I know I am leaving NATO in good hands," he added.
Rutte, a centre-right politician who is the longest-serving prime minister in Dutch history, said his appointment was a "tremendous honour" in a post on X.
Paying tribute to Stoltenberg's leadership, Rutte said he was "grateful to all the allies" for placing their trust in him.
The appointment for an initial four-year term was made by the North Atlantic Council, which is the decision-making body of the alliance made up of ambassadors to NATO.
The Dutch prime minister becomes secretary general at a challenging time for the Western military alliance, facing down a more aggressive Russia and supporting Ukraine amid Moscow's ongoing invasion.
NATO is also concerned about the rising military strength of Beijing and views China as a challenge to the alliance's security.
Rutte, 57, is tasked with the political leadership of NATO and ensuring a consensus can be found within the alliance for difficult issues, especially in times of crisis.
The potential return of former US president Donald Trump to the White House in November would be a major test for Rutte.
Past statements from Trump have cast doubt on US collective defence commitments to the alliance. He has also threatened to withdraw the US from NATO.
Trump also repeatedly criticized what he viewed as low defence spending among European allies.
The NATO secretary general also represents the defence alliance at international level and heads the NATO headquarters as the highest administrative official.
After a decade in the office, Stoltenberg's term is due to end on October 1. His term was extended in March 2022, shortly after the Russian invasion of Ukraine, until September 2023.
Unable to agree on his successor, NATO allies then extended his mandate again until 2024.
The Norwegian is already the second-longest serving secretary general, after Dutchman Joseph Luns who led NATO from 1971 to 1984.
Stoltenberg has earned recognition as a skilful mediator between the sometimes very different interests of the now 32 NATO members, especially shepherding Sweden and Finland into the alliance against initial Turkish opposition.
He is credited with moderating the debate over low defence spending by the European allies, which led to particularly heated debates during Trump's time in office.
He has also had to coordinate NATO’s response to Russia’s war in Ukraine.
Rutte, who became prime minister in 2010, quickly became the frontrunner to be the next NATO chief after receiving the early support of the US, Germany and Britain.
Danish Prime Minister Mette Frederiksen, former British defence minister Ben Wallace and Romanian President Klaus Iohannis were also candidates.
Resistance from Hungary also needed to be overcome after Rutte clashed with Hungarian Prime Minister Viktor Orbán over EU policy, corruption and rule of law issues.