Pentagon chief Mattis questions Syria 'Safe Zones'

United States Secretary of Defence James Mattis questioned the plan on Syrian safe zones, citing Washington was going to study Moscow's proposal.

Mattis asserted that the Russian plan posed many unanswered questions, including whether it would be effective, Sputnik International reports.

"Will it affect the fight against the ISIS [Daesh]? I think the international community is united in the sense of wanting to see the ISIS put on its back foot," the defence secretary said.

"Who is going to be ensuring they're safe? Who is signing up for it? Who is specifically to be kept out of them? All these details are to be worked out and we're engaged."

Mattis' comment was the first public extensive reaction to the Russia-Turkey-Iran-backed plan on the creation of de-escalation zones in war-torn Syria.

"The devil is always in the details, right? So we have to look at the details, see if we can work them out, see if we think they're going to be effective," he continued.

The U.S. owes it "to the situation there, the people there to at least examine it very, very carefully. All wars eventually come to an end. And we've been looking, for a long time, how to bring this one to an end," he concluded.

The representatives of the countries-guarantors of the truce in Syria, on May 4 signed a memorandum on the creation of four zones of de-escalation in Syria, which include the province of Idlib and seven other regions.

According to the memorandum, any clashes between the government forces and opposition armed groups would stop within the zones. The memorandum took effect on May 6.