The US and Russia have reached a breakthrough deal on Syria's peace process that will begin with a nationwide "cessation of hostilities" from sundown on Monday.
The two countries, who have been at odds with one another over the five-year conflict and backed opposite sides, have agreed to launch coordinated air strikes against Isis and other jihadist groups.
If the truce is successful, Russia and the US will begin seven days of preparation work to set up a "joint implementation centre", where they will share information to calculate which opposition groups are in charge of which areas in the war-torn country.
US Secretary of State John Kerry and Sergei Lavrov, his Russian counterpart, announced the detailed plan today after long talks between the pair in Geneva. The latest discussions followed several attempts to pin down a deal over the last two weeks.
However, Kerry has said the joint plan will also require all sides in the conflict, including Bashar al-Assad's regime and opposition groups, "to meet their obligations".
"Today, Sergei Lavrov and I, on behalf of our presidents and our countries, call on every Syrian stakeholder to support the plan that the United States and Russia have reached to... bring this catastrophic conflict to the quickest possible end through a political process," Kerry told a news conference.
"The plan is more prescriptive and far-reaching than any proposal to date and, if implemented by all sides, could allow political negotiations to take place on Syria's future," he added.
Assad's regime will need to agree not to send Syrian military planes into combat missions in an agreed area, while Russian-backed government forces and opposition groups - supported by Gulf states and the US - will need to halt fighting for an unspecified amount of time as a confidence building measure, Reuters reported.
The deal will also allow for improved humanitarian access and, if successful, should enable humanitarian organisations to re-enter hard-to-reach areas such as Aleppo.