Geneva, September 10 (RHC)-- Russia and the United States have reached an agreement on a ceasefire in Syria as part of a plan to find a political solution to the years-long crisis in the Arab country.

Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry announced the agreement during a joint press conference in Geneva, Switzerland, in the early hours of Saturday after some 13 hours of marathon talks on the Syrian crisis.

Washington's top diplomat said that the nationwide truce would be enforced on Monday, the first day of the Muslim holiday of Eid al-Adha (the Feast of Sacrifice), which marks the culmination of the annual Hajj pilgrimage.   The U.S. secretary of state also said if the upcoming truce lasted for a week, Washington would commence military cooperation with Russian forces to target the Takfiri terrorist groups of Daesh and Jabhat Fateh al-Sham, al-Qaeda's Syrian branch formerly known as al-Nusra Front.

Sergei Lavrov, for his part, said that the two countries had agreed to coordinate airstrikes against the terror groups in Syria “provided there is a sustained period of reduced violence.”  He added that after the seven-day truce, Moscow and Washington would establish a Joint Implementation Center, in which the military and the representatives of the two countries’ intelligence would "handle practical issues, separating terrorists and the opposition."

"We will jointly agree on strikes against terrorists to be carried out by the Russian and American air forces.  We have agreed on the zones in which these strikes will be carried out," the Russian foreign minister stated.

“Despite the mistrust and attempt to disrupt what we have agreed upon, we managed to work out a package of documents; there are five of them.  It allows us to set an effective coordination in the fight against terrorism, to expand the humanitarian access to distressed population, first and foremost in Aleppo."   The senior Russian diplomat also noted that Moscow had informed the Syrian government about the arrangements and that it was ready to fulfill them.

Syria has been gripped by foreign-backed militancy since March 2011, much of it organized and financed by the United States and its allies. UN Special Envoy for Syria Staffan de Mistura estimates that over 400,000 people have been killed in the conflict.