Turkey expects Sweden and Finland to take concrete action and halt what it says is their support for "terrorist groups" in order for Ankara to lift its objections to them joining NATO, Foreign Minister Mevlut Cavusoglu said on Friday.

Delegations from the two Nordic countries have returned home with documents detailing Turkey's concerns, like information on terror groups, after a visit this week and Ankara is awaiting their answers, Cavusoglu said.

Finland and Sweden formally applied to join NATO last week and hoped it would be a quick accession process and other NATO members touted the planned enlargement as historic.

However, Turkey challenged the move saying they harbored people linked to the Kurdistan Workers Party (PKK) militant group and followers of Fethullah Gulen, whom Ankara accuses of orchestrating a 2016 coup attempt.

All 30 NATO countries must give their approval before a new member can be admitted and thus benefit from the pact's collective-security guarantee.

Delegations from Sweden and Finland visited Ankara for talks with Turkish officials on Wednesday.

President Tayyip Erdogan's spokesman Ibrahim Kalin said after the talks that Ankara had observed a positive attitude on lifting an arms exports embargo.

However, Kalin later said Turkey would not agree to the two countries joining NATO unless specific steps were taken to address Ankara's objections.

"We have made it very clear that if Turkey's security concerns are not met with concrete steps in a certain timeframe the process will not progress," Kalin told a news conference .

Sweden and Finland banned arms exports to Turkey after an incursion into Syria against the Kurdish YPG militia. Ankara regards the YPG as identical to the PKK and views both groups as terrorist organizations.

(With input from agencies)