This picture shows Turkish President Tayyip Erdogan visiting Hagia Sofia on Sunday. Photo: AFP

President Recep Tayyip Erdogan urged Swedish and Finnish leaders in separate phone calls Saturday to abandon financial and political support for "terrorist" groups threatening Turkey's national security.

Erdogan has objected to the two Nordic nations becoming members of NATO over their failure to address Turkey's terror-related concerns. 

Ankara in particular accused Stockholm of leniency toward the Kurdistan Workers' Party (PKK) listed as a "terrorist" group by Ankara and its Western allies, as well as members of the movement led by US-based Muslim preacher Fethullah Gulen, whom Ankara blames for an attempted 2016 coup. 

Erdogan told Swedish Prime Minister Magdalena Andersson that "Sweden's political, financial and weapon support to terrorist organizations must end," the presidency said in a statement. 

Turkey expects Sweden to "take concrete and serious steps" that show it shares Ankara's concerns over the PKK and its Iraqi and Syrian offshoots, Erdogan told the Swedish premier, according to the presidency.

The Russia-Ukraine conflict starting in February has shifted political opinion in both Nordic countries in favor of joining the Western military alliance. 

Membership requires consent of all 30 existing members but Turkey is putting a spanner in the works.

Sweden and Finland, while solidly Western, have historically kept a distance from NATO as part of longstanding policies aimed at avoiding angering Russia.

But the two nations moved ahead with their membership bid in shock over Russia's operations in Ukraine, which had unsuccessfully sought to join NATO.

AFP