The Damascus regime is trying to "disrupt" the peace process, US Secretary of State John Kerry said. Kerry met with top European diplomats ahead of Syrian peace talks in Geneva.
Washington's most senior diplomat discussed the Syrian civil war with the foreign ministers of France, the UK, Germany and Italy, as well as EU's foreign policy chief on Sunday.
"Against all odds, against most predictions, we have managed to maintain the ceasefire in Syria", Kerry said at the Paris press conference, after returning from the Middle East.
The two-week old Syrian truce has reduced violence by about 80 to 90 percent, according to the US Secretary of State.
"People are sitting in cafes in a way they would have never dared to do two weeks ago," he added.
At the same time, Kerry cautioned the Damascus regime and its "backers" not to test boundaries of the truce.
"The biggest violator, by allegation, is the Syrian regime," he said.
At the joint press conference with the EU diplomats, Kerry also addressed the wave of Syrian refugees heading to Europe.
"In the long run, the only way to end this challenge of refugees is to end the Syrian civil war," he added.
Assad is 'red line' for Damascus
The international partners are looking forward to Syrian peace talks scheduled for Monday, according to the US Secretary of State.
Representatives of the Syrian regime are expected to arrive in Geneva on Sunday, a day ahead before the indirect peace talks with the opposition groups.
However, the regime and its critics continue to publicly clash on the fate of Syrian president Bashar al-Assad, even as their delegates prepare for the diplomatic effort.
The Damascus government insists that the decision about Assad leaving power is an "exclusive right of the Syrian people" and not something to be decided in Geneva.
"We will not talk with anyone who wants to discuss the presidency... Bashar al-Assad is a red line," Syrian Foreign Minister Walid Muallem told a Damascus news conference on Saturday.
Speaking to reporters in Paris, Kerry said that the government was "clearly trying to disrupt the process" with such comments.
The agreed diplomatic approach dictates that "there must be a transition and we must move towards presidential elections at some point," he said.
UN looking ahead
Previously, regime critics told reporters in Geneva that the president needed to go for peace talks to stand a chance.
"We believe that the transitional period should start with the fall, or death, of Bashar al-Assad," chief opposition negotiator Mohammad Alloush told the AFP news agency.
"It cannot start with the presence of the regime, or the head of this regime still in power," he added.
The United Nations is pushing for a transitional government and a new Syrian constitution within the next six months, and legislative and presidential elections to be held next year.
The talks set to open on Monday not expected to last more than ten days, according the UN peace envoy Staffan de Mistura.
Darko Janjevic (AFP, AP, Reuters, dpa)