Washington is discussing with its NATO allies what they can offer Turkey in terms of military assistance in Syria's Idlib, officials said on Tuesday.
It's also discussing measures that may be taken if Russia and the Syrian regime breaks a ceasefire, the officials added.
“We are looking at what NATO can do,” James Jeffrey, the US special envoy for Syria, told reporters in a conference call from Brussels where he was holding talks with allies.
“Everything is on table.”
Jeffrey, who was speaking alongside the US ambassador to Turkey David Satterfield, ruled out the use of ground troops should the ceasefire be broken and repeated that Ankara needed to clarify its stance on purchase of the Russian S400 Air Defence System.
Earlier, Turkey's President Recep Tayyip Erdogan said he was look for "concrete support" from NATO allies in regard to Syria's conflict.
"We expect concrete support from all our allies to this struggle," adding that "NATO is in a critical process in which it needs to clearly show its alliance solidarity" with Turkey.
