The likelihood that Finland joins the NATO military alliance before Sweden had increased, Swedish Prime Minister Ulf Kristersson said on Tuesday, adding that Swedish membership was only a matter of time.

Ever since Sweden and Finland applied to join NATO last year their efforts have been bogged down by Turkey, which claims the two countries host members of Kurdish groups it considers terrorist. Last week, however, the Nordic states’ NATO accession returned to the discussion table in Brussels.

Ankara has not been hiding the fact that its objections to Sweden’s accession have been greater than those to Finland’s. PM Kristersson said Turkey’s position in that regard still remained, meaning Sweden and Finland might not join NATO on the same date.

“What we have encountered in recent weeks is that the probability of this happening at different times has increased,” Kristersson told a news conference in Stockholm prior to his departure for Germany. “At the end of the day, it is not a matter of whether Sweden becomes a member of NATO, but when.”

Turkey acknowledged at the meeting in Brussels last week that both Nordic countries have taken concrete steps to meet Ankara’s concerns, adding that the three countries agreed to hold further meetings as part of the NATO process.

Turkey was embittered in January when Rasmus Paludan, the leader of the far-right, anti-immigrant Danish party Stram Kurs burnt a copy of the Muslim holy book, the Quran, in Stockholm. This prompted Ankara’s reserve towards Sweden’s NATO ambitions and convinced it to suspend talks set up as part of a deal agreed upon in Madrid last year.

For its part, Sweden has stressed it has fulfilled its part of the Madrid memorandum. To address Turkey’s concerns about militants, the Swedish parliament is about to pass new anti-terrorism legislation soon.

In order for Finland and Sweden to become full-fledged NATO members, their accession requires Turkey and Hungary’s ratification as they are the only Alliance members who have not given their thumbs up yet. PM Kristersson said other alliance members were putting pressure on Ankara to speed up ratification.

There are around 17 mosques and over 810,000 Muslim residents in Sweden, which is roughly 8.1 percent of its population.