A senior opposition official said on Tuesday that the postponement of Syria peace talks by the opposition is indefinite with any resumption dependent on "correcting the path of the negotiations" and events on the ground.
"There is no date, the date is ... is the implementation of matters on the ground, and likewise the correction of the path of negotiations. All the while that does not happen, the time period will remain open," George Sabra said.
Sabra also said that the opposition had “big complaints” about US policy which he said sought continued talks “without us obtaining anything real.”
He called on international powers to supply Syrians with the means to defend themselves.
The Kremlin announced on Wednesday it was concerned by a postponement of Syrian peace talks in Geneva, Russian news agencies reported.
"The situation is not an easy one and of course it causes a certain degree of our concern," RIA news agency cited Kremlin spokesman Dmitry Peskov as saying.
After bombardment of market places by regime forces in opposition-held northwest Syria, which killed at least 44 civilians and wounded dozens, Syrian opposition called it a “dangerous escalation” of the conflict.
"These (attacks) represent a dangerous escalation, with the targeting of markets crowded with civilians," a statement from the High Negotiations Committee (HNC) said.
"The massacres ... reinforce the decision taken by the HNC to suspend its participation and postpone the negotiations. No political process can move forward in this atmosphere of killing and criminality."
US, Russia must be ‘sync in’
The United States President Barack Obama said he told Russian President Vladimir Putin on a phone call on Monday that the situation in Syria is quickly deteriorating and they have to work together to move the country forward.
"We're starting to see it fray more rapidly, and if the United States and Russia are not in sync about maintaining it and getting a political track and transition moving, then we could be back in the situation we were three, four weeks ago," Obama said in an interview on Tuesday.
"That would serve neither of our interests," he added.
In their call, Obama and Putin agreed to coordinate their intelligence services and defence ministries more closely.
The Obama administration has repeatedly called for the removal of Syrian regime leader Bashar al Assad and worked with other Western nations to back groups trying to overthrow him, while Moscow remains as the Assad’s the main ally.
Kremlin says peace talks must continue
The Kremlin said on Tuesday that they are supporting the continuation of Syrian peace talks in Geneva postponed by the opposition.
"We believe this (the peace talks) is a necessary condition," Kremlin spokesman Dmitry Peskov said in a conference.
"The need to continue this dialogue and maintain the ceasefire regime was stressed yesterday during the telephone conversation between President Putin and President Obama," he added.
However, Russian Foreign Minister Sergey Lavrov said on Tuesday that Russia and the United States do not support military solution to the Syrian conflict.