The group also met with Riad Hijab, head of Syria’s main opposition body, the High Negotiations Committee which has expressed skepticism that the regime will stick to the truce.
Hijab said a small HNC delegation would travel to Geneva “in the next two days” to meet the worldwide task force monitoring the truce.
U.N. Syria envoy Staffan de Mistura said on Thursday the agreement was holding but remained fragile and incidents had been contained.
The deal was agreed on by Washington and Moscow on February 27.
The Islamic State terrorist group and al-Qaeda-linked Jabhat al-Nusra, groups excluded from the truce, have lost more than 500 fighters due to air strikes by the US-led anti-Islamic State coalition and Russian Federation.
The UK-based Syrian Observatory for Human Rights said that the average number of civilian deaths a day had fallen by 90 percent since the ceasefire came into force nine days ago, with an 80 percent decline among soldiers and rebel forces.
An aid convoy of the Syrian Arab Red Crescent enters the Wafideen Camp, which is controlled by Syrian government forces, to deliver aid into the rebel-held besieged Douma neighborhood of Damascus, March 4, 2016.
World Food Programme spokesman Hussam al-Saleh told AFP that 22 trucks would distribute food, flour and medical supplies to the towns of Hammuriya, Jisreen, and Beit Sawa in Eastern Ghouta.
Military spokesman Igor Konashenkov said in a statement Monday that Russian warplanes continued to bomb Daesh targets and had refrained from attacking groups which support the U.S./Russia-backed agreement.
The HNC would send a representative to Geneva in the next few days to present a precise image to a ceasefire taskforce hosted by the United Nations and chaired by the United States and Russian Federation, he said.
He said that “unfortunately” all Russian airstrikes had been targeting moderate rebels.
The opposition says the agenda must focus on setting up a transitional governing authority – an idea Assad has ruled out on the grounds its contravenes the current constitution.
The Nusra Front is widely deployed across western Syria in close proximity to groups that agreed to cease fire, many of which say they believe the government and its Russian allies can use the presence of the militants as an excuse to fight on.
A resumption of the talks requires a “healthy atmosphere”, Hijab said.
Beginning a Middle East visit, US Vice President Joe Biden admitted that finding a political solution would be hard but there was no other choice.