VILNIUS, Lithuania (AP) — Sweden's foreign minister expressed optimism on Monday that Turkey will drop its objections to Swedish NATO membership, saying the Nordic's country's accession is a question of when, not if.

Turkish President Recep Tayyip Erdogan and Swedish Prime Minister Ulf Kristersson were expected to meet later Monday in the Lithuanian capital, Vilnius, ahead of a two-day NATO summit.

Swedish Foreign Minister Tobias Billström told public broadcaster SVT that he expects Turkey will eventually signal that it will let Sweden join the alliance, though he couldn't say whether that would happen at the annual summit.

“What we are counting on, of course, is to reach a point where we get a message back from President Erdogan that there will be what you might call a green light ... a message that the ratification process in the Turkish Parliament can start,” Billström said.

Turkey has stalled Sweden’s NATO accession, saying it needs to do more to crack down on Kurdish militants and other groups that Ankara considers as threats to its national security. Anti-Turkey and anti-Islam protests in Stockholm raised doubts that an agreement could be reached before the alliance’s summit.

Billström said Sweden has fulfilled its part of a tripartite deal that Sweden, Finland and Turkey signed at last year’s NATO summit in Madrid.

“We should consider it as a settled question in the sense that it is not a question of if. In connection with the NATO summit in Madrid last year, Turkey already gave Sweden status as an invitee to NATO. It is therefore a question of when," he said.

Billström said he expects Hungary, which also hasn't ratified Sweden's accession, to do so before Turkey.

Previously non-aligned Sweden and Finland applied for NATO membership last year following Russia's invasion of Ukraine. Finland joined in April this year.