Russian President Vladimir Putin criticized the US on Saturday for delaying the release of details of a Syrian ceasefire agreement but said Moscow would not make the details public until an agreement with its former Cold War rival had been reached.
"I am not surprised that here they do not follow their basic postulate (of openness and transparency)," Putin said in comments carried by state news agency TASS, speaking after a summit in Kyrgyzstan.
"But we, of course, shall not reveal details until our American counterparts agree to it," the Russian leader said.
Putin suggested that the US wants to keep the deal with Russia secret in order to protect the combat potential of the US-backed Syrian opposition forces in the fight against the regime of President Bashar al-Assad, Moscow's most important ally in the region.
Last week, the United States and Russia announced an agreement on a plan to reduce violence in Syria after more than 12 hours of talks in Geneva.
When the ceasefire launched on Monday, Russia and the US had reportedly agreed that its seven-day success could pave the way for the two world powers to work together for the first time in targeting Islamist militants in Syria.
But Moscow and Washington have traded blame for problems in fully implementing the truce, which has seen several violations.
"Following the fifth day of ceasefire we state that only the Russia and Syrian sides observe fully their obligations," Russian General Staff Viktor Poznihir said on Saturday.
"If the US side does not undertake respective measures to observe the obligations under the agreement of September 9, the responsibility for failing the ceasefire regime in Syria will be on the US," he said in comments carried by TASS.
The ceasefire plan outlined that the Russian-backed Syrian government would not fly combat missions over rebel-held areas, which would allow humanitarian aid to reach people in need. But under the current ceasefire no aid has yet reached Syria's besieged areas.