In response to the recent round of Turkish airstrikes in northern Syria and Iraq, White House National Security Council Strategic Communications Coordinator John Kirby claimed, on Tuesday, that the US is concerned that Turkey's counter-terrorism campaign in northern Syria could "complicate the war against ISIS."

During a press briefing, Kirby said: "Turkey does continue to suffer a legitimate terrorist threat, particularly to their south. They certainly have every right to defend themselves and their citizens. What concerns us about cross-border operations remains the same… that it might force a reaction by some of our SDF partners that would limit and constrain their ability to continue to fight against ISIS [Islamic State]." 

The US wants to keep the pressure on the Islamic State with the SDF, Kirby claimed, adding that the terror group is decreased but is still a real threat.

His remarks came shortly after the spokesperson for the US Department of Defense stated that the US continues to disapprove of any military intervention that would "destabilize Syria or violate Iraq's sovereignty" through military engagements that are not coordinated with the Iraqi government. 

Meanwhile, Syria, Russia, Turkey, and Iran are conducting the 19th session of high-level negotiations of the Astana format summit on the peaceful settlement in Syria in the Kazakh capital, Astana.

Earlier, and in light of the strikes on Syrian territory, Moscow urged Turkey to exercise caution, according to Alexander Lavrentyev, the special presidential envoy of Russia for Syria.

At the beginning of the  19th round of talks on the Syrian settlement in Astana, Lavrentyev said, "We will call on our Turkish colleagues to show certain restraint in order to prevent an escalation of tension, not only in the northern and northeastern regions of Syria but throughout the entire territory."

The envoy emphasized that efforts should be made to find a peaceful resolution to the Kurdish issue while working with all parties involved.

The talks will end on November 23, with representatives from the Syrian government and opposition, as well as the United Nations, taking part in addition to delegations from the format's three guarantor states.

On Sunday, Turkey launched the so-called Operation Claw-Sword with air raids targeting the Kurdish People's Protection Units (YPG) and the Kurdistan Workers' Party (PKK) in both Iraq and Syria.