Mark Rutte, the outgoing prime minister of the Netherlands who has provided more than $3 billion in military support to Ukraine since 2022, on Thursday secured the final support he needs to become NATO’s next secretary general.

Romanian President Klaus Iohannis withdrew his candidacy to lead NATO on Thursday, making it all but certain that Rutte, 57, will be formally elected to a four-year term at the head of the Atlantic alliance.

This could happen as early as next week, ahead of the high-level NATO summit in Washington in July. The Netherlands is a founding member of NATO and Rutte would be the fourth Dutch official to serve as the organization’s top diplomat.

Even if elected, he would not immediately assume responsibility for the 32-nation alliance. Rutte, who has led the Netherlands since 2010, remains prime minister in the country’s transitional government. One diplomat, who requested anonymity in line with protocol, said the current NATO secretary general, Jens Stoltenberg, should stay until his mandate expires in October.

Rutte has increasingly echoed NATO’s core message that supporting Ukraine in its defense against Russia is crucial to preserving democracy and national sovereignty across the alliance.

“This war is not simply about defending the freedom of the Ukrainian people; it is also about protecting the freedom and security of the Netherlands,” Rutte said on his government website. “So we will not abandon those most in need.”

However, Rutte is not seen as reluctant to engage with Russia or Moscow’s few allies in NATO, unlike some candidates from Eastern Europe or the Baltics who had shown interest in the top job.

“It’s a consensual organisation, so there are 32 allies to be involved,” said Camille Grand, former deputy secretary general of NATO, now at the European Council on Foreign Relations. “If you are perceived as leaning towards a particular alliance geography, or too accommodating or too aggressive, then things get complicated.”

“There was a concern that it was important to have someone who was perceived to be at the center of the alliance, rather than on the fringes of the debate,” Grand said. “So it was ticking all the boxes.”

Mr Grand knew and worked with Mr Rutte when they overlapped at NATO headquarters in Brussels. “He was always pretty mainstream in the room,” Mr. Grand said. “He was never difficult about anything, but he was always very pro-NATO, sometimes to the point of criticizing his colleagues when they weren’t loyal enough.”

Rutte’s criticism of Hungary in 2021 was seen as almost costing him the top job at NATO.

Hungary is a member of both NATO and the European Union, and its leader, Prime Minister Viktor Orban, has frustrated officials from both organizations for imposing some authoritarian policies and maintaining relations with Russian President Vladimir V Putin. In 2021, Orban’s government restricted LGBT content in the media and schools, sparking “deep concern” from EU leaders and prompting Rutte to declare that Hungary “no longer has any right to be part of the European Union”.

This led to three years of tension between the two men, and Orban suggested he would not support Rutte’s candidacy to head NATO, whose election requires unanimous consensus within the alliance. But Orban backed down last week as part of an agreement that Hungary would not provide or otherwise support NATO efforts to continue sending military aid to Ukraine for the duration of the war.

In a letter to Orban on Tuesday, Rutte said he would respect that agreement “in a possible future role as NATO Secretary General.”

However, Mr Rutte stopped short of apologizing for his remarks about Hungary.

“I also noticed that some remarks I made in 2021 as Prime Minister of the Netherlands have caused dissatisfaction in Hungary,” Rutte wrote in the June 18 letter. “My priority in a possible future role as NATO Secretary General will be to maintain unity and treat allies with the same level of understanding and respect.”

NATO allies backing Rutte’s candidacy aimed to block further support ahead of the July meeting in Washington. Iohannis, the Romanian president, dropped out of the race after Orban’s concession made it clear that Rutte’s candidacy enjoyed broad support. On Thursday, Iohannis backed Rutte and announced that Romania would send one of its urgently needed Patriot air defense systems to Ukraine.

Rutte announced last July that he would not seek re-election in the Netherlands after his government was divided over Dutch asylum for migrants and refugees.

He told Dutch radio in October that he found the job as NATO’s civilian head “very interesting” and by February he had secured support from the United States and European powers.

Mr. Rutte is unmarried, lives in the same house in The Hague that he bought as a student with friends and often cycles to work.

He is a fan of classical music and U2, and his favorite film is 1979’s “Hair,” according to a 2015 profile in the English-language Dutch News.