Some European leaders jested they’d send Prime Minister Viktor Orban of Hungary their hotel bills for the extra nights they had to spend in Brussels to convince him to support funding for Ukraine.
Others, less jokingly, relayed to him he was facing the risk of a legal suspension from E.U. proceedings. And a few offered a friendly, sympathetic ear over late-night drinks as he complained about what he sees as a European bureaucracy stacked against him out of ideological animus.
By Thursday morning, just one hour into an emergency European Union summit meeting, this carefully coordinated, behind-the-scenes pressure had forced Mr. Orban to fold. After weeks of standing in the way as the only holdout among 27 leaders, he finally agreed to a landmark fund for Ukraine worth 50 billion euros, or $54 billion.
The breakthrough was especially significant for both Ukraine and the European Union. It will help keep Ukraine’s economy afloat for the next four years, even as U.S. aid is stuck in Congress. And it demonstrated European resolve to stand united in support of Ukraine against Russia, and its determination to bring an often obstructionist Mr. Orban to heel.
To get there, Europe’s most important leaders each assumed varied roles to push Mr. Orban into line.
European Council President Charles Michel played the bad cop. On Monday he called Mr. Orban to let him know there was no way he would be granted his demand for an annual veto right over the Ukraine fund.
And he put the E.U.’s “nuclear option” on the table, telling Mr. Orban that some member states were considering launching a procedure that would strip him of his vote entirely — in what would be an unprecedented use of the E.U.’s rule book.
Then, on Wednesday evening, Mr. Orban met with Prime Minister Giorgia Meloni of Italy, his ideological friend from the hard right, in the executive suite of the stately, five-star Hotel Amigo — a staple for visiting dignitaries, tucked away in the heart of Brussels.
Sitting on green velvet armchairs against the leafy wallpaper, over a bottle of champagne, Ms. Meloni told him he had more to gain from the E.U. if he played along. She suggested that a review of the Ukraine fund in 2025 would go some way toward satisfying his need for close scrutiny of the spending. Now was not the moment to dig in.
Next it was the turn of the French president, Emmanuel Macron, who had hosted Mr. Orban for lunch in January in Paris. He met Mr. Orban at the Amigo later on Wednesday evening and suggested that E.U. leaders could include some language in their joint conclusions that would nod to Mr. Orban’s complaint that the E.U. executive branch is withholding funds from Hungary because of ideological bias.
All the while, Mr. Orban knew that a few miles up the street in the European quarter of Brussels, other leaders were meeting to talk about him — without him. A meeting between Mr. Michel; the Dutch prime minister, Mark Rutte; and the German chancellor, Olaf Scholz, confirmed that there was nothing to gain from holding out on the Ukraine fund.
They stood committed that no further concession — like the unfreezing of E.U. money for Budapest, which Mr. Orban had squeezed from his partners before — would be forthcoming.
That word was relayed back to Mr. Orban.
The extraordinary efforts to get Mr. Orban to capitulate reflected both the Hungarian leader’s unique power to play the role of spoiler, as well as the determination of his E.U. partners to secure unanimous agreement to help Ukraine.
Ukraine desperately needs to keep basic services running. The European aid, to be dispensed in the form of loans and grants over the next four years, would both cover immediate needs and allow Ukraine to plan its long-term budget.
Before Thursday, talks had been gridlocked and the mood toward Mr. Orban, the closest E.U. ally of the Russian president, Vladimir V. Putin, had been souring since he blocked the first Ukraine funding attempt in December.
Mr. Orban’s obstruction had been riling his European partners. Small as his country is, Mr. Orban has made himself a big antagonist of E.U. rules and norms.
The European Union and Hungary have long clashed over policies on the rule of law, corruption and minority rights. The European Commission, the bloc’s executive branch, has taken Hungary to task over judicial appointments it says interfere with the independence of the courts; laws that discriminate against L.G.B.T.Q. people; and the defanging of anticorruption authorities.
It blocked Hungary from gaining access to some €20 billion until it can demonstrate that it has altered those policies to bring them in line with E.U. rules and values.
Mr. Orban has also been an outsized obstacle to many of Europe’s ambitions, including some sanctions against Russia and even Sweden’s bid to join the NATO alliance.
He has claimed that his resistance comes down to a fundamental disagreement with other European leaders: He does not believe Russia poses a security threat to Europe, nor does he think that the European Union should be throwing its weight behind Ukraine.
Mr. Orban regularly uses his levers within the bloc — often his ability to veto decisions that require unanimity, such as the introduction of the Ukraine fund — to push Brussels for concessions — including unfreezing money it has withheld from Hungary.
In the current showdown, Mr. Orban had demanded an annual chance to veto the disbursement of money to Ukraine, but that was rejected. Instead, leaders agreed to a regular review of the spending to assuage concerns about diversion or corruption.
Under the agreement, the European Commission will draft a report on how the Ukraine fund is being used. European leaders will have a chance to debate its performance and raise any concerns about it.
The European Parliament needs to approve the fund by simple majority, a bar that should be easily cleared, and the vote could take place as early as this month.
If Mr. Orban’s demand for an annual veto for the Ukraine fund was a play to get access to more funding, it failed.
He managed only to extract a reference in the summit conclusions urging the European Commission to be “proportionate” in the way it freezes funding for member states it punishes for violations, as is the case with Hungary.
Asked whether Mr. Orban gained any concessions in return for withdrawing his veto demand, Ursula von der Leyen, president of the European Commission, told reporters: “The answer to your question is a simple no.”
Still, Mr. Orban insisted he had won the argument as he got ready to head home.
“Mission accomplished,” he said on social media. “Hungary’s funds will not end up in Ukraine and we have a control mechanism at the end of the first and the second year. Our position on the war in Ukraine remains unchanged: we need a ceasefire and peace talks.”
The E.U. was equally triumphant.
“The European Council reconfirmed Europe’s unwavering commitment to stand with Ukraine,” Ms. von der Leyen told reporters. “We know that Ukraine is fighting for us, so we will support them with the necessary funding and provide them with a much needed predictability they deserve.”
The news was warmly welcomed in Ukraine.
“It is very important that the decision was made by all 27 leaders, which once again proves strong EU unity,” President Volodymyr Zelensky of Ukraine wrote on social media. “Continued EU financial support for Ukraine will strengthen long-term economic and financial stability, which is no less important than military assistance and sanctions pressure on Russia.”
Andrew Kramer contributed reporting from Kyiv, Ukraine.