The move by Mr. Wilders shows how much a debate over unauthorized migration continues to roil European politics, a decade after a large-scale influx of people fleeing wars or seeking better economic opportunities unsettled the region.

The governing coalition’s collapse was confirmed by Prime Minister Dick Schoof, who said he would hand in his resignation to King Willem-Alexander on Tuesday. He said he would stay on as the leader of a caretaker government, without Mr. Wilders’s party, until elections and the formation of a new coalition.

It was not immediately clear when the elections would take place, but they appear unlikely to happen before October, plunging the country into political uncertainty for at least the rest of the year. Mr. Wilders’s party has been dropping in Dutch polls lately.

Mr. Wilders announced the withdrawal of his Party for Freedom from the four-party coalition on X, saying the decision was made because of his partners’ refusal to sign off on a new list of proposals to curb migration. “No signature for our migration plans,” he said.

The political crisis comes about two weeks before the Netherlands is set to host a NATO summit on June 24 and 25.

Mr. Wilders’s Party for Freedom — which has advocated banning the Quran, closing Islamic schools and entirely halting the acceptance of asylum seekers — won the largest number of seats in November 2023 elections, sending shock waves through the Dutch political system.

Mr. Wilders was able to form a government with three other right-wing parties — the People’s Party for Freedom and Democracy, a center-right party; the Farmer Citizen Movement, a populist pro-farmer party; and the New Social Contract — after more than six months of wrangling last year. It was the first government to include Mr. Wilders’s party, which mainstream parties had previously shunned.

Together, the four parties hold 88 seats in the 150-seat House of Representatives, a comfortable majority. But in a sign of how uncomfortable their arrangement was, the four agreed not to name any of their own leaders as prime minister. Instead they settled on Mr. Schoof, a career civil servant with no elective office or party affiliation, to lead the government.

Despite a decline in further migrant arrivals, anti-immigrant sentiment remains strong across Europe, fueling far-right populism that has brought politicians like Mr. Wilders to power.

Efforts to limit unauthorized migration have become more mainstream on the continent. In Germany on Monday, a Berlin court ruled that the German border police can no longer reject asylum seekers who arrive from neighboring European Union countries without investigating their claims, dealing a blow to Chancellor Friedrich Merz’s attempts to control such migration.

Mr. Wilders had prided himself on bringing the “strictest migration policy ever” to the Netherlands, something that his governing partners had said they agreed with. In May 2024, the four parties reached a deal that included “the strictest asylum admission policy and the most comprehensive migration control package ever.”

But Mr. Wilders said that implementation of that policy was not going quickly enough. During a news conference last week, he said he wanted to add 10 more proposals to the agreement to further curb migration and demanded the immediate support from his governing partners.

The leaders of the other three parties in the coalition said that while they did not necessarily oppose Mr. Wilders’s plans, they wanted him to propose them in the Dutch House of Representatives. That would have taken longer and would not have guaranteed the plans’ implementation.

Then on Tuesday morning, after an emergency meeting with his governing partners that lasted barely 20 minutes, Mr. Wilders said he had no choice other than to withdraw his party from the coalition.

Dilan Yesilgoz-Zegerius, the leader of the People’s Party for Freedom and Democracy, expressed disbelief over the move. “I am baffled, and I assume his voters are, too,” she said. “I don’t think we will get another right-wing majority.”

Caroline van der Plas and Nicolien van Vroonhoven, the leaders of the other two governing parties, called Mr. Wilders’s decision “irresponsible.”

New elections now seem all but certain, less than two years after voters in the Netherlands went to the polls. The opposition leader Frans Timmermans, who leads the country’s left-wing alliance of the Green Party and the Labor Party, which came in second in the November 2023 elections, said he hoped for new elections “as soon as possible,” effectively ruling out any other option for saving the coalition.