Turkey has accused Sweden of being a haven for "terrorists," especially members of the PKK, and has asked Stockholm to extradite dozens of people.

The accused, who is in his 40s, was arrested in January after making threats and firing a gun outside a restaurant in Stockholm.

The trial is set to start June 20.

Prosecutors say the man's aim was to extort money and use it to finance the Kurdistan Workers' Party (PKK), which is classified as a terrorist organisation by Turkey, as well as Sweden, the European Union and the United States.

The charge comes a week after Sweden's Supreme Court gave the go-ahead for the government to extradite a man supporting the PKK to Turkey, although the government has yet do decide on the matter.

According to Friday's charge sheet, which also references evidence from French and German intelligence, the man had been in contact with people directly involved in funding the PKK and had acted on the group's behalf.

Swedish tightened its anti-terrorism legislation in July last year, making it easier to prosecute financing activities for terrorist organisations.

This is the first time that the new law, already used in cases linked to the Islamic State organisation, has been used against a PKK supporter.

Ending two centuries of neutrality and military non-alignment, Sweden and neighbouring Finland announced bids to join NATO in May last year after Russia invaded Ukraine.

Turkey and Hungary are the only NATO member states yet to ratify the Sweden's bid -- which requires unanimous approval. Finland has already been admitted.

Swedish politicians have meanwhile insisted that the judiciary in Sweden is independent.

Sweden this year passed a law banning more activities linked to extremist groups, which required a constitutional amendment as it was deemed to infringe on Sweden's freedom of association laws.