The Syrian regime's air force would essentially be grounded as most of its bombing has been concentrated on rebel-held areas. The reality, however, is that the zones are now being used in service of a ceasefire the USA never really supported to begin with, and with the US-backed rebels also objecting about the ceasefire getting in the way of their war, the USA will be non-cooperative.
Moscow says the USA, the United Nations and Saudi Arabia also support the idea. Adrian JT Rankine-Galloway, using an alternative acronym for the hardline group.
The Pentagon said the de-escalation agreement would not affect the US -led air campaign against IS. "As for the agreements, we are not a party to that agreement and of course we will never be in favour (of it) as long as Iran is called a guarantor state".
Jordan is not part of the agreement signed in the Kazakh capital Astana to create deescalation zones in Syria, a top government official said on Saturday.
The U.S., on the other hand, has long held the position that Assad must leave power in order to end Syria's ongoing and bitter civil war - a conflict that has left hundreds of thousands dead and has driven millions from their homes.
A State Department official who didn't want to be identified told CNN, "The United States supports any effort that can genuinely de-escalate the violence in Syria, ensure unhindered humanitarian access, focus energies on the defeat of ISIS and other terrorists, and create the conditions for a credible political resolution of the conflict".
It said, additonally, "In light of the failures of past agreements, we have reason to be cautious".
Russian Federation suspended the agreement a month ago following a US missile strike on a Syrian air base in response to a deadly chemical gas attack that has been blamed on the Syrian government forces.
Syria's rebels have expressed their reservations over a Russia-backed "de-escalation zones" deal and are protesting Iran's role in guaranteeing the agreement.
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The words were an apparent references to the Bible verse that begins "For God so loved the world, that he gave his only Son". This update contradicts a previous report which claims Hernandez had used synthetic marijuana hours before killing himself.
The Britain-based Observatory said it had recorded no civilian casualties yet on Saturday, but that several fighters were killed in regime bombardment of Daraa and Aleppo provinces in the first reported deaths since the deal came into effect.
The call came as a Russia-initiated plan to set up safe zones was to take effect.
It said the agreement "lacks the minimal elements of legitimacy" and also rejected any role for government ally Iran as a guarantor of the deal.
The Syrian government supported the de-escalation plan, but said it would continue to fight what it termed "terrorist" groups.
Russian Federation and Iran - two of the plan's three sponsors - are key allies of President Bashar Assad's government and both are viewed as foreign occupation forces by his opponents.
Nauert also says the US -backed Syrian opposition must live up to its commitments. Teams of global observers would monitor the safe zones.
In the tangled mess that constitutes Syria's battlefields, there is much that can go wrong with the plan, agreed on in talks Thursday in Kazakhstan.
Turkey, Iran and Russian Federation have signed an agreement calling for the setting up four "de-escalation zones" in war-torn Syria in the latest attempt to reduce violence in the Arab country.
Lavrentyev suggested that all military aircraft, including Russian and Turkish, are prohibited. But the full details of the proposal were not made available and prospects for its success appeared bleak.
In Washington, Pentagon spokesman Captain Jeff Davis told reporters the USA -led coalition in Syria had not altered its operations, but declined to comment on the de-escalation zones. However, no details were provided about how violence will be reduced in these areas.