"We understand and respect Turkey's concerns regarding its own security. We believe this is the legal right of Turkey," Kremlin spokesman Dmitry Peskov told reporters.

"We still call on all parties to refrain from steps that could lead to seriously destabilising the situation," he said.

He added that it could "boomerang back and further complicate the security situation".

Turkey on Sunday launched a series of air raids targeting bases of outlawed Kurdish militants across northern Syria and Iraq.

At least 37 people were killed in the strikes, according to a report by Britain-based monitoring group the Syrian Observatory for Human Rights.

On Monday strikes from Syria killed at least two people, including a child, in the Turkish border town of Karkamis.

The Kremlin's comments came as representatives from Russia, Turkey and Iran -- major players in the war in Syria -- meet in the Kazakh capital Astana for trilateral talks on Syria.

Russia's special envoy on Syria, Alexander Lavrentyev, told reporters earlier in Astana that "We hope to convince our Turkish colleagues to refrain from resorting to excessive use of force on Syrian territory" to "avoid the escalation of tensions".

"Russia has for months ... done everything possible to prevent any large-scale ground operation," Lavrentyev said in the Kazakh capital.

Russia, Iran and Turkey are major players in the war in Syria, which has claimed nearly half a million lives since 2011.

Turkish President Recep Tayyip Erdogan has been threatening to launch a new military operation in northern Syria since May.

"We will make those who disturb us on our territory pay," he said on Monday, adding that consultations were ongoing "to decide the level of force that should be used by our ground forces".

The Turkish air offensive, codenamed Operation Claw-Sword, came a week after a blast in central Istanbul killed six people and wounded 81, an attack Turkey has blamed on the outlawed Kurdistan Workers' Party (PKK).

The PKK has waged a bloody insurgency in Turkey for decades and is designated a terror group by Ankara and its Western allies. But it has denied involvement in the Istanbul explosion.

burs/yad