Russia on Friday said it was sending two warships armed with cruise missiles to waters off the Syrian coast and blamed Ankara for the killing of 33 Turkish soldiers in Syria’s Idlib region the previous day.

The killing of the Turkish soldiers on Thursday and the wounding of 32 others, announced by the governor in Turkey’s Hatay province bordering Syria, raised the Turkish military death toll in the region to 54 this month.

NATO's secretary-general called on Russia and Syria on Friday to halt the offensive in Idlib and said, after a meeting of the alliance's ambassadors, that NATO stood in solidarity with Turkey.

"We call on Russia and the Syria regime to stop the attacks, to stop the indiscriminate air attacks ... we also call on Russia and Syria to fully respect the international law," Jens Stoltenberg told a news conference."We call on Syria and Russia to fully engage in UN-led efforts to find a peaceful solution for the conflict in Syria."

NATO ambassadors met on Friday to hold consultations about developments in Syria under Article 4 of the alliance's treaty at Turkey's request, NATO Secretary General Jens Stoltenberg said, after the killing of 33 Turkish soldiers in a Syrian air strike in the Idlib region.

Open gallery view A protest in support of the Turkish army and Turkey backed Syrian rebels at the Bab el-Salam border crossing in Syria, February 25, 2020. Credit: Khalil Ashawi/ REUTERS

Russian President Vladimir Putin and Turkish President Tayyip Erdogan agreed during a phone call on Friday on the need for new measures to be put in place to ease tensions and normalize the situation in northwest Syria, the Kremlin said.

In a readout of the phone call, the Kremlin said Putin and Erdogan agreed to organise a top-level meeting to address the situation in Syria's Idlib province that the presidents said was a matter of "serious concern".

Turkish Foreign Minister Mevlut Cavusoglu had spoken to Stoltenberg by phone late on Thursday.

Turkey has sent thousands of troops and heavy military hardware into Syria and Erdogan has warned that Turkey will launch a full-scale offensive to repel Syrian forces unless they pull back from Turkish observation posts in the region.

Though trying to coordinate their efforts on Syria, Russia backs Syrian President Bashar al-Assad, while Turkey backs rebel forces opposing Assad.

Responding to Thursday’s killings, a senior Turkish official said on Friday that Ankara would no longer stop Syrian refugees from reaching Europe. Turkey blamed an air strike by Syrian government forces for the deaths.

Russia’s Defence Ministry was cited by the RIA news agency on Friday however as saying that the Turkish troops had been hit by artillery fire from Syrian government forces who were trying to repel an offensive by rebel forces.

It was quoted as saying that Ankara had failed to notify Moscow of the presence of Turkish troops in the area hit by shelling despite being in regular communication with the Russian military.

Nearly a million Syrians have been displaced in the last three months by fighting between Turkish-backed rebels and Syrian forces trying to recapture the last major insurgent-held region in Syria after nine years of war.