The Turkish president told journalists that he still intends to prevent Finland and Sweden from joining NATO. Recep Tayyip Erdoğan said that this week's meetings with Finnish and Swedish delegations were "not at the expected level," pointing out that no steps have been taken to alleviate Turkey's security concerns.

He told journalists on board his plane after a visit to Azerbaijan on Saturday, according to the daily "Hürriyet," that "as long as Recep Tayyip Erdoğan is at the head of the Republic of Turkey, we cannot say 'yes' to countries that support terrorism joining NATO."

Erdoğan referred to an interview broadcast on Swedish official television with Salih Muslim, a member of the Syrian Kurdish administration in northeastern Syria, on the night of the delegation meeting, citing this as proof of Sweden's support for the Syrian Kurdish militants whom Turkey considers an extension of a banned Kurdish group that has led a rebellion against Turkey since 1984.

Erdoğan said, "They are not sincere," pledging not to allow countries harboring terrorists to join the alliance. He also accused Germany, France, and the Netherlands of making the same "mistake" by supporting terrorism.

The Syrian Kurdish People's Protection Units, or YPG, form the backbone of the US-led forces fighting against the Islamic State.

Turkey has been fighting the Kurdistan Workers' Party since 1984 within Turkey and northern Iraq, where it has intensified operations, and Ankara has also led operations in Syria to push this party away from its borders.

Turkey, which leads the second largest army in the coalition, said it will not allow Sweden and Finland to join unless steps are taken, including lifting restrictions on arms sales to Turkey. Erdoğan added that he will speak by phone with Russian and Ukrainian leaders on Monday.