A senior deputy from Turkey's main opposition Republican People's Party (CHP) called on the UN to intervene in the crisis in Syria's Idlib province.
Speaking to journalists in the parliament on Tuesday, CHP's parliamentary group acting chairman Engin Altay said that the Idlib issue was "a national security issue" for Turkey.
"The UN should immediately intervene in Idlib," said Altay.
"Turkey should hold intense talks with all opposition parties in Idlib to push for cease-fire," he added.
The Syrian regime recently announced plans to launch a major military offensive in Idlib, which has long been controlled by various armed opposition groups.
The UN warned last week that such an offensive would lead to the "worst humanitarian catastrophe in the 21st century".
Located near the Turkish border, Idlib is home to more than 3 million Syrians, many of whom fled from other cities following attacks by regime forces.
On Friday, Erdogan called for a cease-fire in Idlib during a tripartite summit in Tehran with Iranian President Hassan Rouhani and Russian President Vladimir Putin.