"Due to reasons we cannot completely understand, the US did not agree on sharing the texts of the documents with you and even with representatives of the UN Security Council. But I will read fragments of these two documents to make it clear," Churkin told reporters after an emergency meeting of the Security Council.
The council held a meeting after US-led coalition warplanes attacked Syrian Army troops on Saturday.
Two F-16 fighters and two A-10 ground attacks aircraft entered Syrian airspace and bombed positions of the Syrian Army near Deir ez-Zor, leaving at least 62 personnel killed. The US Central Command later said that the airstrike was an accident.
On Friday, a UN Security Council meeting on Syria was expected but Russia decided to cancel it due to Washington’s unwillingness to make the deal public.
In addition, Churkin expressed doubts that the UNSC would pass a resolution to support the deal.
"Russia and the US are going to take joint efforts to stabilize the situation in Syria, including special measures near Aleppo. The priorities are separating territories controlled by Daesh and al-Nusra Front from territories controlled by moderate opposition forces, as well as separating moderate rebels from al-Nusra Front militants," Churkin cited the agreement.
He also cited extracts from a document agreed between Washington and Moscow in July.
"The goal of a Joint Implementation Group is establishing broad coordination between the United States and the Russian Federation. The parties, the US and Russia, will work together within the framework of a Joint Implementation Group in order to defeat al-Nusra Front and Daesh. They will work in order to maintain a ceasefire and support a political transition process described in Resolution 2254 by the UN Security Council," Churkin said.
"Those preparations were very important. They could change the situation and intensify efforts against al-Nusra Front and Daesh. They also could create better conditions for a political process," the special envoy added.
Earlier this week, Russian President Vladimir Putin commented on the issue.
"The only reason why they apparently don’t want to make it public is because the international community, as well as American and Russian public will immediately find out who is not abiding by the deal," Putin said.
The president stressed that al-Nusra Front militants should be separated from opposition groups but Washington has not made progress on the problem.
On September 9, Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry announced a new plan on Syria, which stipulates a ceasefire that came into force on Monday.
A ceasefire came into force across Syria on September 12. The next step is establishing a Joint Implementation Center which would coordinate Russian and American airstrikes against al-Nusra Front, Daesh and other terrorist groups.