"Sweden is working diligently towards a quick and seamless entry into NATO," Billstrom told a press conference in Berlin after meeting Germany's foreign minister.

"I will shortly go to Ankara this autumn to continue discussions with my counterparts there," Billstrom said.

Sweden and Finland dropped decades of military non-alignment and scrambled to become NATO members in May, after Russia invaded Ukraine.

But Turkey has threatened to block their bids and sought concessions, leading to a deal in June with the Nordic states that included provisions on extraditions and sharing information.

New Swedish Prime Minister Ulf Kristersson visited Ankara on Tuesday to meet President Recep Tayyip Erdogan in the hope of persuading the Turkish leader to drop his objections.

Following the meeting, Erdogan said a joint meeting would be organised in Stockholm later this month, without specifying the date.

Kristersson's trip to Ankara showed there was "still plenty room for dialogue", Billstrom said Thursday.

"I think the discussions are continuing in a very positive way," he said.

Finland, Sweden and Turkey would continue their joint talks on accession as well, Billstrom said.

"When all conditions laid down in the memoranda have been fulfilled, the Turkish parliament will be ready to ratify," he said.