Russia, Turkey and Iran agreed to calm the situation in northern Syria by implementing relevant agreements, Reuters reported on Thursday.

In a joint statement following talks in Kazakhstan, the three countries announced that they decided to deploy more efforts to ensure the stability of the situation in the de-escalation zone in Syria’s Idlib.

According to Reuters, the three countries “highlighted the necessity to maintain calm on the ground by fully implementing all agreements on Idlib”, without specifying what that meant for Turkey’s plans to carry out a military operation against the Kurdush-led People’s Protection Units (YPG) there.

Several agreements have been concluded between Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin, including the Sochi Memorandum of 2019, in which Turkey committed to stop its military operation dubbed the “Peace Spring.”

It also included the establishment of a demilitarized zone and deployment of joint Russian-Turkish patrols ensure a ceasefire.

Meanwhile, the Russian Foreign Ministry said Moscow expressed its “grave concern” to the Israeli ambassador on Wednesday, following the air strikes that closed Damascus International Airport last week.

Inbound and outbound flights were suspended until further notice, following the raids.

Syria has been a close ally of Moscow, since Russia launched a military campaign in 2015 that helped turn the tide of the war in favor of President Bashar al-Assad.

“Serious concern was again expressed over the June 10 Israeli air force attack on the civilian airport of Damascus, which damaged the runway, navigation equipment and buildings, and disrupted international civilian air traffic,” the ministry said after Deputy Foreign Minister Mikhail Bogdanov met Israeli Ambassador Alexander Ben Zvi in Moscow.

“The ambassador was told that the justification received from the Israeli side regarding the strike … was unconvincing and that Moscow expected additional clarification,” it added.