President Recep Tayyip Erdogan has confirmed Turkey’s opposition to NATO membership for Finland and Sweden, shooting down a proposal by the Nordic countries to send delegations to Ankara to address the matter.

“We will not say ‘yes’ to those [countries] who apply sanctions to Turkey to join security organisation NATO,” Erdogan said at a news conference on Monday, referring to Sweden’s 2019 decision to suspend arms sales to Turkey over its military operation in neighbouring Syria.

Turkey also accused the two bidding nations of harbouring “terror” groups, including the Kurdistan Workers’ Party (PKK), blacklisted by Ankara, the European Union and the United States.

“Neither of the countries have a clear stance against terror organisations,” Erdogan said. “How can we trust them?”

Justice ministry sources told the state news agency Anadolu on Monday that Sweden and Finland had failed to respond positively to Turkey’s 33 extradition requests over the past five years.

Ankara wanted individuals that are either accused of having links to the PKK and allied groups or of belonging to a movement blamed for the attempted overthrow of Erdogan in 2016, the agency reported.

Turkey has rebuked Stockholm especially for showing what it describes as leniency towards the PKK, which has waged an armed uprising against the Turkish state since 1984.

The Swedish foreign office said earlier on Monday that senior representatives of Sweden and Finland were planning to travel to Turkey for talks to address Ankara’s objections.

Erdogan reacted to the comments by saying: “Will they come to persuade us? Excuse us, but they shouldn’t bother”. He added that NATO would become “a place where representatives of terrorist organisations are concentrated” if the two countries join.

Ankara’s approval will be necessary for Finland and Sweden to be able to join NATO, as membership bids must be unanimously approved by the alliance’s 30 members.

Stefanie Babst, former NATO deputy assistant secretary-general for public diplomacy and an analyst at the European Leadership Network, told Al Jazeera that “Turkey will, in the end, align with the consensus and welcome Finland and Sweden as new members”.

“In the meantime, they will try to bargain in negotiations in order to get some returns,” she said.

Turkey may be aiming to obtain military equipment from Washington to upgrade its outdated F-16 fleet and ratchet up some Western support to relieve its troubled economy. On the home front, the analyst said the mention of the PKK was aimed at drawing the support of Erdogan’s nationalist voters.

Ankara’s latest rebuke came after Sweden’s government formally decided to apply for NATO membership. Prime Minister Magdalena Andersson made the announcement on Monday, a day after Finnish President Sauli Niinisto confirmed that Finland will also apply for membership.

“We are leaving one era behind us and entering a new one,” Andersson told a news conference, adding that the application could be handed in on Monday, Tuesday or Wednesday and would be synchronised with Finland.

Turkey surprised its NATO allies last week by saying it would not view their applications positively.

On the sidelines of a meeting of NATO foreign ministers in Berlin on Sunday, Ankara adopted a more conciliatory tone and laid down its demands, saying it wanted the two countries to end support for groups such as the PKK and lift the ban on arms sales.

US Secretary of State Antony Blinken on Sunday stated that Sweden and Finland would be able to join NATO despite Turkey’s concerns. NATO Secretary-General Jens Stoltenberg also said he was confident “that we will be able to address the concerns that Turkey has expressed”.

Turkish Foreign Minister Mevlut Cavusoglu is scheduled to meet with Blinken in Washington on Wednesday, where Ankara’s objections are expected to figure high on the agenda.