When NATO leaders gather this summer to celebrate the 75th anniversary of their military alliance, the last thing they want to see is a resurgent Russian army marching through Ukraine because Europe was too weak to give Kiev the support it needed.

What Ukraine ultimately wants is a formal invitation to join NATO. But alliance officials agree that won’t happen at the festivities planned in Washington in July. NATO has no desire to confront a new member who, because of the alliance’s collective security pact, would drag it into the biggest ground war in Europe since 1945.

This has led NATO to seek a middle ground, something other than membership but substantial enough to show that it is backing Ukraine “for the long term,” as NATO Secretary General Jens Stoltenberg put it this week. .

It has so far proven elusive, according to senior Western diplomats involved in the discussions.

Proposals presented this week at a meeting of foreign ministers in Brussels to give NATO more control over the coordination of military aid, financing and training of Ukrainian forces were immediately met with skepticism. The United States and Germany remain opposed to offering Ukraine a start in membership talks in Washington as they did at last year’s summit in Vilnius, and want that issue taken off the table in July, despite a similar process in the European Union that was approved last year. winter. But they do want to offer Ukraine specific commitments that it can fulfill. Efforts to clearly define what conditions Ukraine must meet to start talks with NATO have not yet moved forward.

And none of these things may matter come July if Russia continues to gain ground and Ukraine appears in danger of losing the war, a prospect that has become more real each month that Republicans in Congress continue to block a $60,000 aid package. million dollars for kyiv.

“The situation on the ground may look much worse than it is today, and then the real question is: ‘How do we make sure Russia doesn’t win?'” said Ivo H. Daalder, a former U.S. ambassador to NATO. .

“That can change the whole nature of the debate. We can all think that the NATO summit will be held as if it were the same as today, but it will not be like that,” said Daalder, president of the Chicago Global Affairs Council. “The last two months have not been good for Ukraine and there is nothing in sight that will improve.”

Last year, at a NATO summit in Vilnius, Lithuania, Ukraine was once again assured that it would one day be granted full membership in the alliance, after it made certain changes to improve democracy and its security. The vague promise dismayed Kiev and its most ardent supporters in the Baltics, the Nordic states and Eastern Europe.

Nine months later, Ukraine is dealing with the aftershocks of a military counteroffensive that burned precious artillery ammunition and other weapons while failing to gain any appreciable territory from Russia. The country remains in urgent need of weapons, particularly for air defense; Its Foreign Minister, Dmytro Kuleba, said Thursday that Ukraine was hit by 94 Russian ballistic missiles in March alone.

“I didn’t want to ruin NATO’s birthday party, but I felt obliged to deliver a very sobering message on behalf of the Ukrainians about the state of the Russian airstrikes against my country, which destroy our energy system, our economy, kill civilians,” Kuleba said Thursday at NATO headquarters in Brussels.

Kuleba said he had “listened carefully” to his diplomatic colleagues discussing how NATO could address Ukraine’s place in the alliance in Washington this summer and had carefully responded in kind.

“It is up to the allies themselves to decide the form and content of the next step towards Ukraine’s membership in NATO,” he said. “We will look forward to the outcome, but of course we believe that Ukraine deserves membership in NATO and that this should happen sooner rather than later.”

Stoltenberg sought to close the gap by presenting two proposals at this week’s meeting for continued support for Ukraine that he said he hoped could be approved in time for the NATO heads of state meeting in Washington in July.

The first, making NATO and not the United States responsible for coordinating donations and arms deliveries to Ukraine, drew objections from Hungary and other allies over its potential to drag the alliance more directly into war. The United States is also opposed, Daalder said, although the Biden administration has so far been careful not to publicly criticize him. On Thursday, Secretary of State Antony J. Blinken addressed the issue only by praising the current US-led process for its “extraordinary results.”

The other, giving Ukraine $100 billion in aid over five years, was met with confusion, as it is unclear how NATO could force its member states to contribute, especially given budgetary or political constraints such as the of the United States Congress, which has delayed 60 billion dollars for Ukraine.

But Stoltenberg said such plans were vital to ensure Ukraine continued to receive lasting support from NATO rather than piecemeal donations. (He did, however, applaud recent shipments of drones, missiles, armored vehicles and ammunition from Britain, the Czech Republic, Finland, France and Germany.)

Stoltenberg added that NATO’s top military commander, US Army General Christopher G. Cavoli, had been asked to devise a plan to provide reliable and predictable aid to Ukraine in the years ahead.

“If NATO allies do what we must, then we have absolute confidence that the Ukrainians will be able to make further progress,” Stoltenberg said. “That’s why we need to offer more, why allies need to dig deeper and provide more military support faster, and why we also need stronger, more robust long-term structures.”

A backdrop to this urgency is NATO’s desire for “Trump-proof” (as it has been called in recent months) Western support for Ukraine should former President Donald J. Trump be re-elected in November. Trump has long been disdainful of NATO, mocking its members for not paying a “fair share” of security costs and, in February, suggesting that if a European member of the alliance were attacked by Russia, he would not help defend it. If only I had done it. he has not paid his share.

On Thursday in Brussels, Blinken said he heard “from ally after ally” that “our commitment, our commitment, is indispensable to this alliance” and its support for Ukraine. He said Ukraine was working on the government and security changes needed to join NATO, and outlined without detail several efforts within the alliance to offer the war-weary country new guarantees when leaders meet in Washington in July. .

However, it was clear from his comments that the world should not expect a sharp change in the status quo.

“These conversations over the last few days have focused on exactly what we’re going to do at the summit,” Blinken said. “We have started a process between all the countries and with all the experts to give substance to that. “We will use the time between now and the summit to do exactly that.”

Steven Erlanger contributed reporting from Berlin.