"I have a sense that we will find formulations which will not disappoint Ukrainians and will convey more than we are used to saying," Gitanas Nauseda told AFP in an interview on Tuesday.

Ukrainian President Volodymyr Zelensky, whose country is battling Russian forces, "might not receive everything he expects in his most ambitious plans, but he will certainly receive a lot," Nauseda added.

Zelensky said last week he wanted "a very clear and understandable signal" at the summit that Ukraine could become a NATO member after the war.

His administration also hinted that the Ukrainian head of state would drop his plans to visit Vilnius if the expectations were not met.

Ukraine applied for expedited NATO membership last year, seven months after Russia launched a full-scale invasion of the neighbouring country.

Nauseda said Lithuania and several other countries are advocating for a stronger signal for Ukraine in the summit's declaration.

"There are definitely not just one, two, or even four member states that would like to see a more ambitious text, and currently dialogue is taking place between those countries and more cautious states," Nauseda said.

"I hope it will end in a mutually acceptable way," he added.

He said that the summit will take decisions to establish a NATO-Ukraine council and individual allies will provide security guarantees to Kyiv, including economic and military assistance.

He also expressed hope that Zelensky would attend the summit.

- Last-minute suspense -

Though Ukraine will be the summit's number one priority, Lithuania also hopes the talks will produce additional pledges for NATO's eastern flank.

Several months ago, allies began negotiations for new regional defence plans, which will involve the allocation of forces and capabilities with high readiness levels.

Lithuania had initially hoped to reach an agreement on the plans before the summit. Nauseda said it remains possible, though he expressed reservations about "last-minute decisions".

"Some individuals prefer to maintain the suspense until the last minute. Perhaps the decision itself seems more thrilling when it is announced almost as the curtain goes down," Nauseda said.

"However, I believe that in order to achieve a more composed and consistent outcome, it is preferable to avoid last-minute decisions," he added.

Defence Minister Arvydas Anusauskas told journalists on Wednesday that while allies generally agree on the plans, some of them are "holding off" to secure their desired outcomes in other NATO-level negotiations.

At the summit, allies are also expected to underscore a recent agreement on a new rotational model for air and missile defence in the region.

However, Nauseda said he did not expect allies to provide specific commitments just yet to contribute by deploying land-based systems due to their limited availability.

"I fear that we will not have precise details on this matter at the Vilnius summit," he added.