Sweden must stop protests by supporters of outlawed Kurdistan Workers' Party (PKK) in Stockholm to get a green light on its NATO membership bid, Turkish President Tayyip Erdogan told NATO's Secretary-General in a phone call on Sunday.

Erdogan told Stoltenberg that Turkey had a constructive attitude, but Sweden's change of terrorism laws to meet demands from Ankara was "meaningless" while PKK supporters hold protests in the country, the Turkish presidency said in a statement.