The Turkish delegation arrived in Moscow on Monday, a day after President Recep Tayyip Erdogan said tens of thousands of Syrians were heading toward Turkey amid a Syrian-Russian operation against militants in the Arab country’s northwestern province of Idlib.

Erdogan warned that his country, which already hosts some 3.7 million Syrian refugees, could not handle a new influx of refugees from Syria, and urged an end to the operation in Idlib, which is the last major stronghold of militants in Syria.

Russia is an ally of the Syrian government while Turkey supports anti-government militants in the conflict.

Syrian President Bashar al-Assad has vowed to recapture Idlib. In recent days, Syrian ground forces have recently advanced in several areas in the province.

Meanwhile, a Turkish diplomatic source said his country’s delegation would also discuss Turkey’s potential troop deployment to Libya. Ankara signed a security and military cooperation deal with the Libyan government last month. Russia has expressed concerns about any such deployment.

Later on Monday, the Turkish Foreign Ministry said Minister Mevlut Cavusoglu had held a phone call with his Russian opposite number, Sergei Lavrov, to discuss developments in Syria and Libya, without elaborating.

Reporter’s code: 50101