The summit will address the alliance’s most pressing challenges, agree on steps to further strengthen NATO's deterrence and defense and bring Ukraine closer to the alliance.
"The decisions we will take in Vilnius will bring Ukraine closer to NATO...Bolstering NATO's deterrence and defense will also be high on the agenda of our summit," said NATO Secretary General Jens Stoltenberg.
Allies will take major steps towards the latter goal with the adoption of three new regional defense plans to counter the two main threats to NATO: Russia and terrorism.
According to Stoltenberg, 300,000 troops at heightened readiness along with significant air and naval combat capability will support the plans.
In addition, allies are required to support a Defense Production Action Plan that aims to "aggregate demand, boost capacity, and increase interoperability" as well as a more ambitious defense investment commitment to spend at least 2% of yearly GDP on defense.
Sweden's accession to NATO following Finland is one of the main agenda items. As Stoltenberg announced a day ahead of the summit, Türkiye has agreed to send Sweden's NATO Accession Protocol to parliament following a trilateral meeting between himself, Turkish President Recep Tayyip Erdogan and Swedish Prime Minister Ulf Kristersson.
"I'm glad to announce that President Erdogan has agreed to forward the Accession Protocol for Sweden to the Grand National Assembly as soon as possible and work closely with the assembly to ensure (its) ratification," Stoltenberg told a press briefing in Vilnius.
"Sweden agreed today, as an EU member, also to support actively the efforts to reinvigorate Türkiye's EU accession process, and also to help to modernize the EU-Türkiye customs union and visa liberalization," he said.
Last week, Hungary, which also has not ratified Sweden's accession, said it will back Türkiye's decision on Sweden's bid to join NATO.
"If there is a shift (in Türkiye's decision), then of course we will keep the promise that Hungary will not hold up any country in terms of membership," Foreign Minister Peter Szijjarto told a news conference in Budapest.
On Wednesday, a heads of state and government level meeting of the NATO-Ukraine Council will take place.
Regarding the meeting, Stoltenberg said earlier that he expects allied leaders to agree to a package with three elements to bring Ukraine closer to NATO.
The package will include a multi-year program of assistance to ensure interoperability, upgraded political ties, and a reaffirmation that Ukraine will become a member of NATO, with unity on how to bring Ukraine closer to its goal.
However, the NATO chief has often stressed that Ukraine would not join the alliance while the war with Russia continues.
