HELSINKI - Finland and Sweden are committed to joining the NATO military alliance simultaneously, the Nordic neighbours' prime ministers said on Friday.

Sweden and Finland launched their bids to join NATO in May in response to Russia's invasion of Ukraine, but ran into objections from Turkey, which accuses the two of harbouring what it says are militants from the banned Kurdistan Workers Party (PKK) and other groups.

All NATO members except Turkey and Hungary have ratified the applications.

"It is very important for us, of course, that Finland and Sweden would join NATO hand in hand," Finnish Prime Minister Sanna Marin told reporters, adding that she had discussed Turkey's concerns with its President Recep Tayyip Erdogan in Prague recently.

"He stated ... that there isn't that many questions when it comes to Finland, (but) some questions when it comes to Sweden," she said.

Swedish Prime Minister Ulf Kristersson, who took office last week, said during a visit to Helsinki he was not worried that Sweden would be left behind in the process by Finland, and that he would meet with Erdogan in Ankara in the near future.

"It's completely legitimate that Turkey gets confirmation that Sweden is doing what Sweden has committed to do within the framework of the agreement," he said.

(Reporting by Anne Kauranen in Helsinki and Simon Johnson in Stockholm editing by Anna Ringstrom)