Turkey's Prime Minister Recep Tayyip Erdogan told NBC on Thursday that the red line in Syria was crossed a "long time ago," saying he is sure Syrian President Bashar al-Assad "has used chemical weapons and missiles" against his own people.
His comments came as Syrian officials said they would cooperate with a United Nations probe into the use of chemical weapons after all. Deputy Foreign Minister Faisal Muqdad told Agence France Press on Thursday: "We were ready and we are always ready, right now, to receive the delegation that was set up by [UN chief] Ban Ki-moon to investigate what happened in Khan al-Assal." Syrian officials earlier expressed resistance to a nationwide probe.
More from GlobalPost: Syria: A timeline of 'red line' rhetoric (VIDEO)
Syria is the scene of rising violence with forces loyal to Assad fighting an armed uprising in a conflict that has taken an estimated 70,000 lives over the past several years.
The rebels and the regime have been trading accusations over the use of chemical weapons there, a move US President Barack Obama earlier stated would cross a "red line," raising the possibility of foreign intervention.
The debate came to a head after 30 people were reported killed in the village of Khan al-Assal near Aleppo in March, with the regime and rebels accusing one another of using chemical weapons there. The UN has said it will not limit its investigation to that particular area, however.
"It is clear the regime has used chemical weapons and missiles," Erdogan told NBC on Thursday, citing evidence among the many Syrian refugees who have fled to Turkey since violence began.
More from GlobalPost: Turkish doctors say no nerve gas in Syrian victims' blood
The Turkish premier also referred to "remainders of missiles" suggestive of chemical warfare, listing as many as 200 to NBC.
As for the rebels, Erdogan was skeptical they had access to chemical weapons.
"There is no way I can believe in this now," he said. "First of all, how are they going to obtain this? And who will give this to them? But if it exists, we are against this...We are against whoever holds the weapons," he said, denying that the Turkish government was giving the rebels military support.
Watch Erdogan's full interview with NBC here:
Visit NBCNews.com for breaking news, world news, and news about the economy