Three Turkish soldiers were martyred and 10 others wounded Thursday in a suspected Syrian regime air attack close to the city of Al-Bab in northern Syria.
In his remarks during an interview on state-run broadcaster TRT, Yildirim said the cause of the attack was being investigated by Turkish officials.
"Our general staff's military contact with related officials is still continuing. The warning has been given to the officials, certainly and clearly, not to repeat the attack."
'Turkey wants to improve relations with Shanghai Cooperation Organization'
Yildirim also addressed Turkey's developing relations with the Shanghai Cooperation Organization.
Yildirim said that Turkey's relations with the organizations was neither a threat nor a challenge to the European Union.
"The Far East countries including, China, Russia, Middle Asian countries want their relations [with Turkey] to develop, both economically and politically. We also want to improve our relations."
Yildirim added that Turkey had not put forward the idea of being a member of the Eurasian political, economic, and military alliance as a rejection of the EU accession talks.
He also drew attention to the negotiation process regarding the new constitution. Negotiations primarily involve the four parties represented in parliament
Yildirim said Turkey would "definitely" not conduct an early election. "The presidential election and parliamentary elections will be carried out in 2019."
"After 2019, the presidential system will virtually be in full force and effect. By then, the transition process will be completed. Thousands of legislations will be renewed."
The ruling Justice and Development, or AK, Party has sought to introduce a presidential system to replace the current parliamentary model since Recep Tayyip Erdogan became the first head of state elected by popular vote in August 2014.
This new constitutional draft needs 330 votes in parliament before the legislations go to a referendum. The AK Party, with 316 seats, and the Nationalist Movement Party, or MHP, with 40, both back the bill.
If the draft constitution gets more than 367 votes, it can pass directly without the need for a referendum. However, the AK Party has said it will take the new constitution to a referendum, even if none is needed.
Criticism of European motion
Yildirim also slammed a European Parliament motion Thursday that urged the EU to halt accession talks with Ankara.
The premier said without Turkey refugees would invade Europe. "The EU should see it. The breakage of the relations would harm Turkey but do more harm to the European Union," Yildirim said.
Turkey hosts the largest number of Syrian refugees in the world, and has so far spent more than $20 billion - $25 billion for their care, according to Yildirim.
Syria has remained locked in a vicious civil war since early 2011, when the Bashar al-Assad regime cracked down on pro-democracy protests with unexpected ferocity.
Since then, more than 250,000 people have been killed and more than 10 million displaced, according to UN figures.