Turkey's defense minister and his U.S. counterpart discussed during a telephone call, the latest situation in Idlib, northwestern Syria, the Turkish Defense Ministry said Thursday.

According to a ministry statement, Hulusi Akar and Mark Esper exchanged views on finding a solution to the Idlib conflict, bilateral and regional defense and security issues.

Esper later added on Twitter that he and Akar "discussed the Assad regime’s brutal aggression in Idlib, which is backed by Russia & Iran; the resulting humanitarian crisis; & Libya."

"We're exploring ways the US can work together w/Turkey & the international community," the U.S. defense secretary added.

In September 2018, Turkey and Russia agreed to turn Idlib into a de-escalation zone in which acts of aggression are expressly prohibited.

But more than 1,300 civilians have been killed in attacks by the regime and Russian forces in the de-escalation zone since then as the cease-fire continues to be violated.

More than 1 million Syrians have moved near the Turkish border due to intense attacks.

*Michael Hernandez contributed to this report from Washington