Peskov said that Russia and Turkey will jointly investigate the deadly incident. The Kremlin spokesman said that Putin told Erdogan that Turkish soldiers had died as a result of lack of coordination regarding coordinates during Russian military jets' strikes in Syria.
Russia and Turkey will improve coordination of activities in Syria after the unintentional strike, Peskov said.
"President Putin informed… about the recent telephone conversation with Turkish President Erdogan, said that he expressed condolences to the Turkish counterpart over the fact that early this morning as a result of non-coordination of coordinates Turkish soldiers had been killed during a joint operation to liberate al-Bab by Russian Aerospace Forces' airstrikes," Peskov said.
Earlier in the day, the Turkish General Staff said that an accidental Russian airstrike killed three Turkish soldiers and wounded 11 others in northern Syria.
"Today, around 08.40, during airstrikes against Daesh targets [in Syria], Russian combat planes accidentally hit a building hosting Turkish servicemen taking part in Euphrates Shield operation. As a result, three Turkish soldiers were killed, 11 were wounded, including one seriously," the Turkish General Staff said in a statement.
The Russian Defense Ministry has also confirmed the unintentional strike, killing Turkish servicemen in Syria. The ministry said that Russian bombers had been on a mission to destroy Daesh terrorists' positions near al-Bab, where Turkish soldiers had been accidentally bombed.
"Russian bombers have been carrying out a combat mission destroying Daesh positions in al-Bab area. The chiefs of the [Russian and Turkish] general staffs agreed to closer coordinate joint actions and exchange information about the situation on the ground."
Chief of the Russian General Staff General Valery Gerasimov held telephone talks with his Turkish counterpart, during which the issues of the fight against international terrorist groups in Syria and the situation in the northeast of the province of Aleppo were discussed.
"Chief of the General Staff of the Armed Forces of the Russian Federation Army General Valery Gerasimov expressed condolences to [Turkish] General Hulusi Akar in connection with the death of three Turkish soldiers operating in the area of the city of al-Bab as a result of unintentional strike by a Russian aircraft."
The news comes as the Turkish military operation in Syria's al-Bab has entered the final stage. Turkey's units entered central al-Bab, the operation is being conducted in coordination with Russia to prevent clashes with Syrian government forces.
Russian and Turkish military jets have repeatedly jointly bombed Daesh targets near al-Bab in Syria. Al-Bab is one of Daesh’s last remaining strongholds near the Turkish border. Capturing the city is of strategic importance to Turkey in order to prevent the Syrian Kurds taking it and unifying their own territories.