Ankara will not stand by and watch the loss of civilian lives in Syria, Turkish President Recep Tayyip Erdogan has warned, after a trilateral summit with the leaders of Iran and Russia, reports Al Jazeera.

In a series of tweets on Friday following the meeting in Tehran, Erdogan said disregarding civilian lives would "play into the hands of terrorists."

"If the world turns a blind eye to the killing of tens of thousands of innocent people to further the regime's interests, we will neither watch from the sidelines nor participate in such a game," Erdogan said.

Turkey, he reiterated, was committed to the voluntary and safe repatriation of refugees and a lasting solution to the Syrian conflict.

Iran's President Hassan Rouhani hosted his Russian and Turkish counterparts - Vladimir Putin and Erdogan  - on Friday amid growing concern over a looming humanitarian catastrophe in Idlib.

The province hosts more than three million people, half of whom are internally displaced. The summit ended without an agreement as Turkey pushed for a ceasefire that was rejected by Russia and Iran, raising fears of an imminent offensive in Idlib by the Syrian government.

Russia and Iran back Syrian President Bashar al-Assad, while Turkey supports some of the rebels, who seek al-Assad's removal.

However, in a joint statement, Iran, Russia and Turkey said that the Syria crisis could only reach a final resolution through a "negotiated political process", not military means.

The statement also called for the creation of conditions safe enough to allow the return of those displaced by the seven-year conflict.

The talks in Tehran were held as Russian and Syrian fighter jets continued bombing various areas of southern Idlib province, killing several people, according to activists.