BRUSSELS — NATO leaders will agree next week to help modernize Ukraine’s armed forces, create a new high-level forum for consultations and reaffirm that it will join their alliance one day, the organization’s top civilian official said Friday. But the war-torn country will not start membership talks soon.

At a two-day summit starting Tuesday in the Lithuanian capital, Vilnius, U.S. President Joe Biden and his counterparts will also agree to boost defense spending as allies pour weapons, ammunition and other support like uniforms and medical equipment into Ukraine, 17 months into the war.

They also hope to welcome Sweden as the next member of the world’s biggest security organization, if they can overcome Turkish President Recep Tayyip Erdogan’s objections, even though its accession would only be made official in coming months.

“For 500 days, Moscow has brought death and destruction to the heart of Europe, seeking to destroy Ukraine and divide NATO,” NATO Secretary-General Jens Stoltenberg told reporters on Friday. “At the summit, we will make Ukraine even stronger, and set out a vision for its future.”

Stoltenberg said the leaders “will agree a multi-year program of assistance to ensure full interoperability between the Ukrainian armed forces and NATO.”

A NATO-Ukraine Council – where crisis talks can be held – will be established. Ukrainian President Volodymyr Zelenskky will attend the council’s first meeting in Vilnius on Wednesday

Stoltenberg said the leaders “will reaffirm that Ukraine will become a member of NATO and unite on how to bring Ukraine closer to its goal.” NATO first pledged that Ukraine would become a member one day in 2008, but things have evolved little since then.

Asked when, or how, Ukraine might join, Stoltenberg said that the “most important thing now is to ensure that Ukraine prevails.” The U.S., Germany and some other allies consider that Ukraine should not be invited in while it’s at war, so as not to encourage Russia to widen the conflict.

With Ukraine imploring its Western partners for more weapons and ammunition, and national military stocks among its partners depleting, NATO is encouraging the 31 allies to boost their military budgets.

In 2014, NATO allies pledged to move toward spending 2% of GDP on defense by 2024. In Vilnius, they will make 2% the minimum, but will not set any time frame for achieving that goal, NATO officials say. Under new estimates released Friday, only 11 of the allies will reach the 2% goal in 2023.

But Stoltenberg said that good progress is being made. “In 2023, there will be a real increase of 8.3% across European Allies and Canada. This is the biggest increase in decades,” he said, adding that European Allies and Canada will have invested over $450 billion extra since 2014.

Question marks remain about Sweden’s future at NATO. It abandoned a long history of military nonalignment last year to seek protection under the organization’s security umbrella after Russia invaded Ukraine.

Erdogan appears set to steal the summit limelight. He accuses Sweden of being too lenient toward groups that Ankara says pose a security threat, including militant Kurdish groups and people associated with a 2016 coup attempt.

Hungary is also holding up approval of Sweden’s candidacy, but has never clearly stated publicly what its concerns are. NATO officials expect that Hungary will follow suit once Turkey lifts its objections.

The other 29 allies, Stoltenberg and Sweden have all said the country has done enough to satisfy Turkey’s demands. Sweden has changed its constitution, modified anti-terror laws and lifted an arms embargo on Turkey, among other concessions.

NATO requires the unanimous approval of all 31 members to expand.

Stoltenberg, Erdogan and Swedish Prime Minister Ulf Kristersson will hold talks in Vilnius on Monday in an attempt to break the deadlock.