It is important for the world to unify behind a plan that will bring about political transition in Syria, White House spokesman Jay Carney said Monday.
"..It's obvious that history will judge [Syrian President Bashar] Assad a a brutal dictator who murdered his only people," Carney told reporters. "History will judge those that supported Assad and continue to support Assad, accordingly."
Carney stated that is essential that "the world community come together and unify to pressure Assad and isolate Assad, and help precipitate a situation where that political transition can take place."
Carney's comments followed another violent weekend in Syria. Syrian rebels killed at least 80 army soldiers at the weekend, an opposition watchdog said on Monday, in a surge of attacks that followed their threat to resume fighting if Assad failed to observe a UN-backed ceasefire.
The latest violence and Assad's defiant speech
to parliament on Sunday raised questions about how long UN-Arab League envoy Kofi Annan can realistically pursue his threadbare peace plan.
The Syrian Observatory for Human Rights said local doctors had confirmed the names of 80 dead government soldiers.
Insurgents told the British-based group they had killed more than 100 soldiers and destroyed some tanks in clashes across Syria, including Damascus and Idlib province in the northwest.
Syria's state news agency reported the burial on Monday of 30 members of the security forces killed by rebels.
Some commanders in the rebel Free Syrian Army had announced last week they would be "free of any commitment" to Annan's peace plan if Assad did not end violence by Friday.
The May 25 massacre of at least 108 people, nearly half of them children, in the Houla area of Homs province dealt a possibly fatal blow to Annan's proposed ceasefire, which was supposed to take effect on April 12 but never did.
A Syrian troop pullback was at the top of Annan's six-point plan to halt hostilities, allow peaceful protests, supply humanitarian aid and start a political transition in a country controlled by the Assad family with an iron fist for 42 years.
"The Annan mission is essentially dead, and of course most Western powers admit that," said Michael Stephens, researcher at the Royal United Services Institute's branch in Qatar.
"Houla changed the game completely in terms of what people were willing to accept and what they were not."