Last week, a Swedish-Finnish delegation traveled to the Turkish capital Ankara to discuss the countries' NATO applications with Turkey.
On Sunday, Erdogan announced in an interview with the Turkish state channel TRT Haber that the talks had not reached the "expected level".
"As long as Tayyip Erdogan is the leader of the Republic of Turkey, we can definitely not say yes to countries that support terrorism becoming members of NATO," Erdogan said.
"Relevant to understanding"
Erdogan points to an interview that "Swedish state television" broadcast last week with Salih Muslim, leader of the Kurdish party PYD in Syria, which also has a military branch called the YPG.
He believes that the interview is one of several proofs that Sweden is not taking the necessary measures required to reach an agreement.
- They are not honest, not sincere, he says in the interview.
SVT Nyheter's responsible publisher Charlotta Friborg says that SVT covers a number of issues that are relevant to Sweden's NATO application.
- The question of the view of the Kurdish party PYD is part of what Turkey presents as a stumbling block.
Hearing PYD representatives is relevant as part of the understanding of the whole process.
PYD's representatives also get tough questions about the organization's possible connections to the PKK, and the PKK is a terrorist organization, which the PYD is not, says Friborg.
"Remarkable and surprising"
How do you view Erdogan's statement?
- I think it is remarkable and surprising that a head of state has views on an independent newsroom's choice of interviewees, says Charlotta Friborg.