In a statement released late on Wednesday, de Mistura is said to be engaged in "high-level consultations... with the aim of proactively ascertaining the options" for kick-starting the UN-facilitated political process as called for in Security Council resolution 2254.
Voted unanimously by the 15-member body in 2015, the resolution calls for free and fair elections for all Syrians and a newly-drafted Constitution as the basis for a Syrian-led, Syrian owned process to end the conflict.
More than seven years of war in Syria between rebels and forces loyal to President Bashar al-Assad has claimed hundreds of thousands of lives, displaced millions and razed entire cities to the ground, the UN said.
De Mistura has conducted nine rounds of negotiations between the warring Syrian sides. The eighth round of talks held in Geneva in December collapsed and were followed by Vienna talks in late January.
As part of his bid to re-launch the Syrian peace talks, de Mistura met Foreign Ministers from several countries taking part in an Arab League summit in Saudi Arabia last weekend.
The veteran negotiator was due to head this week to Turkey, Russia and Iran for discussions with senior officials, according to his team.
De Mistura is also expected to consult European ministers and senior representatives from the US at a conference in Brussels on April 24-25 to support Syria and the Middle East including bolstering the UN-led peace process.
The statement by follows a warning by UN Secretary General Antonio Guterres at the weekend that tensions risk escalating beyond Syria.
Guterres' call came in response to air strikes by the US, France and Britain which followed an alleged chemical weapons attack on the rebel enclave of Douma outside Damascus on April 7 which the Syrian government denies it was behind.
The Organisation for the Prohibition of Chemical Weapons (OPCW) reported on Wednesday that a UN-led security team sent to assess the sites of the suspected attacks and prepare for the arrival of OPCW inspectors was forced to withdraw after it came under gunfire and an explosive was detonated.
"At present, we do not know when the (Fact-finding Mission) team can be deployed to Douma," OPCW chief Ahmet Uzumcu said.
The OPCW team is due to look into the alleged use of toxic chemicals, reportedly chlorine, at the sites which reportedly left dozens dead and dozens more injured.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
