Turkey’s President Recep Tayyip Erdogan agreed to back Sweden’s bid to join NATO, clearing the latter’s pathway to become a part of the military alliance.

“Completing Sweden’s accession to NATO is a historic step that benefits the security of all NATO allies at this critical time. It makes us all stronger and safer,” NATO Secretary General Jens Stoltenberg said on the eve of the two-day NATO summit in Vilnius, Lithuania.

Erdogan had blocked the move for a year, approving Finland’s bid first. Ankara’s objections were complex, but centered mainly on Sweden’s support for Kurdish groups that Turkey considers to be terrorists, and on weapons embargoes that both Sweden and Finland, along with other EU countries, imposed on Turkey for targeting Kurdish militias in Syria.

The hold up spurred protests against Turkey in Sweden’s capital, which escalated at the beginning of the year when far-right demonstrators burned a Quran. The move was swiftly criticized and threatened to derail Sweden’s NATO membership bid.

NATO said Sweden and Turkey have cooperated closely to address the latter’s security concerns since last year’s summit.

“Sweden has amended its constitution, changed its laws, significantly expanded its counter-terrorism cooperation against the PKK, and resumed arms exports to Turkey,” the statement said, referring to the Kurdish Workers’ Party which Ankara had designated as a terrorist organization.

The nations also agreed that counterterrorism cooperation is a long-term effort, which will continue beyond Sweden’s accession to NATO.

U.S. President Joe Biden praised the development, saying “I stand ready to work with President Erdoğan and Türkiye on enhancing defense and deterrence in the Euro-Atlantic area.”

Turkey greenlighting the bid was, however, something that had been “predicted for some time,” especially if Erdogan were reelected for a third term as he would no longer need to use the issue to rally nationalist support, said William Courtney, adjunct senior fellow at RAND.

Prior to Turkey’s elections in May, the country’s presidential spokesperson in March said that Ankara had “left the door open” to Stockholm’s bid to be a part of the military alliance.

NATO’s expansion along Europe’s eastern flank with Finland and Sweden’s membership could also make the military alliance “much stronger,” Courtney added.

“The addition especially of Finland up in the northern flank, brings a whole new capability for NATO along the eastern edge.”