I am not entirely sure what this means since the US and Russia are not fighting each other in Syria and there are lots of other factions that will pay no attention to this.
At best, it heroically means that the US and Russia will stop their military involvement in the hell hole.
Via The New York Post:
The US and Russia have reached a ceasefire agreement over the conflict in southwest Syria, officials announced Friday, as President Trump and Russian leader Vladimir Putin met for the first time at the G-20 summit in Germany.
The ceasefire will go into effect Sunday at noon Damascus time, officials told the Associated Press.
Other details of the agreement weren’t immediately released.
US allies Jordan and Israel, which share a border with the southern part of Syria, are also part of the agreement.
A ceasefire in four zones outlined in a new Syria peace plan is scheduled to go into effect Saturday, a Russian envoy to de-escalation talks told reporters, according to state media.
The ceasefire will last six months and could be "automatically extended" for another six months, Alexander Lavrentyev said Friday after talks in Astana, Kazakhstan.
Turkey's state-run Anadolu news agency also reported on the ceasefire -- signed by Russia, Turkey and Iran -- saying a joint working group will be set up by the agreement's three guarantor countries to determine the precise borders of the four zones by June 4.
The security zones would be in place in Idlib province, to the north of the city of Homs, in Eastern Ghouta near Damascus, and in southern Syria.
Such zones, also referred to as non-conflict or safe zones, are meant to be areas where civilians can live without being targeted by any party in Syria's war. However, key issues would involve whether and how the zones would be enforced.