Dunford, the chairman of the Joint Chiefs of Staff and General Valery Gerasimov chatted on the phone hours after a new Syria ceasefire plan creating "de-escalation" zones went into effect with the backing of Russia, Iran and NATO-ally Turkey. The deal also calls for refugees to be allowed to return to the safe zones and services and infrastructure to be restored.
If it worked, the ceasefire could be extended with the agreement of all parties, a memorandum said on Saturday. It raised the prospect that after years of government opponents asking the USA and its allies for a no-fly zone to protect civilians from the Syrian military's bombings, it could end up being Russia, Syria's ally, that imposes one.
The six-year old Syrian civil war has resulted in the death of at least 400, 000 people, with half of the population said to have fled the country since. He did not elaborate on who those countries might be.
The walkout and the comments underline the huge difficulties of implementing such a deal.
The Syrian government and rebel groups are not signatories to the agreement, but state news agency SANA said Damascus supports the plan.
A previous cease-fire agreement that went into effect on December 30 helped reduce overall violence in Syria for several weeks but eventually collapsed. After past failures, this deal provides for the first time a mechanism to observe the cease-fire: Russian, Iranian and Turkish troops are to monitor compliance on the ground.
Russia, Turkey and Iran agreed in a memorandum signed on May 4 to establish four separate de-escalation zones in Syria after rounds of talks in Kazakhstan capital Astana. U.N. Secretary-General Antonio Guterres said he was encouraged by the agreement.
On Thursday, UN Special Envoy for Syria Staffan de Mistura also hailed the plan.
Syrian opposition forces have not signed on to the deal and walked out of the Kazakhstan talks in protest over previous violations by Assad forces and their Russian supporters.
The deal - which was agreed on Thursday and published today - will see four "de-escalation zones" established for a period of six months.
Russian Federation and Iran are the ones carrying the main responsibility for observance of the memorandum on safe zones in Syria, the German Foreign Ministry said Saturday. The U.S. and Russian Federation signed the memorandum in 2015 when Russian Federation began its air operations in the country.
There were limited reports of bombing in northern Homs and Hama, two areas expected to be part of the "de-escalation zones", after midnight.
The Syrian opposition rejected the Russian plan to create safe zones, calling it a threat to the Syria's territorial integrity.
The Syrian government has said that although it will abide by the agreement, it would continue fighting "terrorism" wherever it exists, parlance for most armed rebel groups fighting government troops.
The four main battlegrounds covered are the northwestern province of Idlib, parts of central Syria, the south, and the opposition enclave of Eastern Ghouta near Damascus.
It was not clear how a cease-fire over such a broad and logistically complicated area would be achieved, or whether worldwide observers would be sent to Syria to monitor its implementation.
"Jordan is taking part in the Astana talks as an observer and the deal was between three countries; Russia, Iran and Turkey", the official added.
In those areas, combat operations, including flights by military aircraft, are outlawed as of May 6.
Political and armed opposition groups in Syria have rejected the proposal, saying Russian Federation has been unwilling or unable to get President Bashar al-Assad and his Iranian-backed militia allies to respect past ceasefires.
Syria's war has claimed more than 300,000 lives since it erupted in 2011.
"We will send this list to the Russians via the Turks", the source said, speaking on condition of anonymity.
This photo provided by Azaz Media Office, a Syrian anti-government activist group, which has been authenticated based on its contents and other AP reporting, shows Syrian citizens and civil defense workers gathering next of burning vehicle at the explosion scene, in Azaz town, north Syria, Wednesday, May 3, 2017.
Fighter jets fired at the rebel-held village of al-Zalakiyat and nearby positions in the northern Hama countryside, where the combatants exchanged shelling, the Britain-based war monitoring group said.
SDF has been on the offensive in Tabqa since mid-April.