Leaders of Turkey, Iran and Russia reached an agreement on the composition of a Syrian constitutional committee, in a meeting held in Ankara on Monday.

"We had an earlier dispute on one member of the committee; now it is resolved," Turkish President Recep Tayyip Erdogan said during a joint news conference.

Russian President Vladimir Putin said the committee, which consists of members of the opposition and the Syrian government, would begin to draft a constitution after determining its own procedures in coordination with the United Nations.

However, the leaders didn’t see eye to eye on some issues, including the humanitarian crisis in Idlib and the presence of the People’s Protection Units (YPG) - a Kurdish militia that Turkey views as a terrorist group - in northern Syria.

Iranian President Hassan Rouhani, and others, expressed concerns about the presence of militant groups in Idlib and the worsening humanitarian situation there, yet none gave any guidance on how the Syrian refugees' plight there could be alleviated.

Syria's Idlib is 'slowly disappearing', Recep Tayyip Erdogan says Read More »

"We will continue to support the Syrian army’s limited counter-terror operations in Idlib. Our agreements don’t include terror groups," Putin said.

Erdogan said extra measures to protect Turkish military outposts in Idlib would be put in place.

In a joint statement, the leaders also rejected what they called "illegitimate self-rule initiatives" and opposed "separatist agendas" in northeastern Syria, a reference to the US-backed Syrian Democratic Forces' (SDF) bid for Kurdish autonomy.

However, while Erdogan underlined his strong opposition to the YPG's presence in the area, calling the group "terrorists", the other leaders didn’t follow suit.

Without being specific, Rouhani noted that efforts were needed to counter terrorist groups in northern Syria. Putin said the presence of the Islamic State (IS) group in northeastern Syria was worrying.

“The Syrian [government] entering this area is [key] to reaching long-term security,” he said.

Meanwhile, all three leaders condemned Washington's support for the "illegal annexation of the Golan Heights" by Israel.

"[We] consider Israeli military attacks in Syria as destabilising and violating the sovereignty and territorial integrity of this country," the joint statement added.

Israel has carried out dozens of air strikes against pro-government forces, including Lebanon's Hezbollah, in Syria in recent years.