The UN's special envoy to Syria Staffan de Mistura thanked Turkey for its acceptance of Syrian refugees during his meeting with Turkish Foreign Ministry Undersecretary Feridun Hadi Sinirlioglu in Ankara Wednesday, the Anadolu Agency reported.

"De Mistura conveyed his appreciation for the substantial effort by Turkey in welcoming and hosting a large number of Syrian refugees," the envoy's spokeswoman Jessy Chahine said in a statement released from Geneva.

"The special envoy also stressed the importance of the contribution of the regional countries to a political solution to the Syrian conflict."

Turkey has taken in 1.8 million of the 4 million refugees who have fled the war-torn nation since violence erupted in 2011, according to the UN’s refugee agency.

De Mistura has been holding talks in an attempt to implement the Geneva Communique that sets out a six-point plan to stop the violence and move the sides in Syria towards a political settlement.

He has been to Egypt, Qatar, and UAE last week to hold talks with officials aimed at finding a political solution for the Syrian crisis.

More than 40 Syrian groups, including armed opposition groups, have been invited to attend talks that began in May.

The civil war has led to the deaths of more than 220,000 people.