Türkiye agreed to advance Sweden's accession to the North Atlantic Treaty Organization (NATO) on Monday, a day before the alliance's summit in the Lithuanian capital, NATO Secretary-General Jens Stoltenberg announced. 

Stoltenberg said at a press conference following a three-party meeting with Turkish President Recep Tayyip Erdogan and Swedish Prime Minister Ulf Kristersson that Türkiye has agreed to forward Sweden's accession protocol to the parliament as soon as possible and ensure its ratification.

The NATO accession process requires the approval of all member states. Sweden and Finland applied to join the alliance last year, but faced objections from Türkiye, which argued that the two countries harbor members of the outlawed Kurdistan Workers' Party (PKK) and the Gulen movement.

Türkiye eventually lifted its objection to Finland's NATO accession earlier this year after Helsinki took "concrete steps" against such organizations. In April, Finland became NATO's 31st member state. However, Ankara continued to block Sweden's NATO bid.

The NATO chief said that since the 2022 NATO summit, Sweden and Türkiye have worked together closely to address Türkiye's legitimate security concerns.

"Sweden has amended its constitution, changed its laws, significantly expanded its counter-terrorism cooperation against the PKK, and resumed arms exports to Türkiye, all steps set out in the Trilateral Memorandum agreed in 2022," he said.

The two countries agreed to continue their cooperation under the Trilateral Permanent Joint Mechanism within the framework of the Trilateral Memorandum, and also under "a new bilateral Security Compact that will meet annually at ministerial level and create working groups as appropriate," he added.

Earlier on Monday, before leaving for Vilnius, Erdogan said that his country would support Sweden's joining of NATO if the EU revived membership talks with Ankara, an unexpected move that some media claimed would "rock the alliance's unity."

The long-awaited decision has won support from the leaders and officials of other countries. Hungarian Prime Minister Viktor Orban has signaled he will follow Erdogan's lead.

U.S. President Joe Biden said, "I look forward to welcoming Prime Minister Kristersson and Sweden as our 32nd NATO ally," and German Foreign Minister Annalena Baerbock also welcomed the "good news" on Twitter.

Sweden's NATO membership has been a key focus at the Vilnius summit. Ahead of the alliance's meeting, several organizations in Sweden have stepped up to voice their objections to the country's joining of the alliance. The Swedish Peace and Arbitration Society told Dagens Nyheter newspaper last week that the country would be safer not belonging to a military alliance.

It is "a historically bad prioritization – Sweden safer outside NATO," said Kerstin Bergea, the society's chairperson. "I am afraid that we will escalate the tense world situation by becoming part of a nuclear weapons alliance."

(With input from agencies)