Turkish President Recep Tayyip Erdogan said on Thursday he may meet Syria’s Bashar al-Assad as part of a new peace process, after their defense ministers met last week for the highest-level talks between the two foes since the Syrian war began in 2011.

In a speech in Ankara, Erdogan said the next step, following the landmark talks between defense ministers in Moscow, would be a trilateral meeting of the foreign ministers from Turkey, Russia and Syria, to further develop contacts.

“We have launched a process as Russia-Turkey-Syria,” Erdogan said. “We will bring our foreign ministers together and then, depending on developments, we will come together as leaders.”

Turkey has been the primary backer of Syria’s opposition for more than a decade of war, while Russia has backed the Syrian government.

The conflict, which has killed hundreds of thousands of people, displaced millions and drawn in regional and world powers, has ground on into a second decade, although fighting is at a lower intensity than in earlier years.

With backing from Russia and Iran, al-Assad’s government has recovered most Syrian territory. Turkish-backed opposition fighters still control a pocket in the northwest, and Kurdish fighters backed by the United States also control territory near the Turkish border.

A Turkish official said the Turkish and Syrian defense ministers met in Moscow on December 28., with the topics of migration and Kurdish militants on the agenda.

Turkish-Syrian rapprochement seemed unthinkable earlier in the conflict, and Syria’s opposition has urged Turkey to reaffirm its support.

Ankara has sought to reassure the opposition, with Defense Minister Hulusi Akar saying Turkey would not take any step that would cause problems for them, Al Arabiya reports.