Niinisto told a Finnish news agency on Saturday that if Helsinki and Stockholm's NATO membership was not achieved by the summer, the process of joining the bloc would become even more uncertain.
The Finnish leader recalled that NATO had promised Helsinki and Stockholm rapid accession to the alliance, but the process had unexpectedly stalled due to Ankara's position.
"I don't think that he [Turkish President Recep Tayyip Erdogan] will succumb to any public pressure. But if something opens up in bilateral negotiations between the United States and Turkey, then maybe this will have an effect," Niinisto said, Sputnik reported.
Sweden and Finland abandoned neutrality and applied for NATO membership in May 2022 after Russia launched its military operation in Ukraine. Their accession protocols have already been ratified by all NATO members except Hungary and Turkey.
The process came to a standstill in January 2023 after Rasmus Paludan, the leader of Danish political party Stram Kurs, burned copies of the Quran in front of the Turkish embassy in Stockholm with permission from the Swedish authorities. Erdogan then condemned the demonstration and said Sweden should not count on Ankara's support for its NATO bid. Furthermore, Erdogan warned last month that Turkey may take a decision on Finland's NATO membership that would "shock" Sweden.
MNA/PR