"Syria is at a pivotal moment. And so are we," Ban told the U.N. General Assembly Thursday. "Syria and the region can quickly move from tipping point to breaking point. The dangers of full-scale civil war are imminent and real."
The secretary-general said despite accepting U.N.-Arab League Special Envoy Kofi Annan's six-point peace plan, the government of President Bashar Assad was not honoring or implementing the plan. He urged the world community to unify to end the carnage in Syria.
"Today's meeting comes in the wake of the recent massacre in Houla, where 108 people, including 49 children, many of whom were under age 10, were killed, as well as reports of large-scale killings in Maazratt al-Qubeir, near Hama, which the U.N. Supervision Mission in Syria is currently trying to verify."
"We condemn this unspeakable barbarity and renew our determination to bring those responsible to account, said Ban. "The situation in Syria continues to deteriorate. Each day seems to bring new additions to the grim catalogue of atrocities."
The White House press office issued a statement on Syria Thursday deploring the targeted killing of civilians and said the country's future will be determined by the Syrian people.
"There is no justification for this regime's continued defiance of its obligations under the Annan Plan, and Assad's continued abdication of responsibility for these horrific acts has no credibility and only further underscores the illegitimate and immoral nature of his rule," the statement said.
Ban said the Annan plan and international support for it was key to ending the violence. "We must continue to support it with stronger steps to ensure compliance," he said. "No one can predict how the situation in Syria will evolve."
U.S. Secretary of State Hillary Clinton also spoke out Thursday against violence in Syria, saying, "The regime-sponsored violence that we witnessed again in Hama [Wednesday] is simply unconscionable. Assad has doubled down on his brutality and duplicity, and Syria will not, cannot be peaceful, stable or certainly democratic until Assad goes."
In Syria, U.N. observers were blocked in their attempts to reach the site of the reported massacre.
Syrian activists have claimed government troops and militiamen massacred at least 78 villagers near the city of Hama, a report the Syrian government denied.
The U.N. Supervision Mission in Syria, which is monitoring an all-but-ignored cease-fire, sent observers to the village early Thursday.
"Their mission is being obstructed by three factors: First, they are being stopped at Syrian Army checkpoints and in some cases turned back; second, some of our patrols are being stopped by civilians in the area; third, we are receiving information from residents of the area that the safety of our observers is at risk if we enter the village," Maj. Gen. Robert Mood, the head of the U.N. Supervision Mission in Syria, said in a statement.
"Despite these challenges, the observers are still working to get into the village to try to establish the facts on the ground," he added.
Activists also said Syrian forces, backed by militias, slaughtered civilians in the town of Heffe, although no other information about this incident has been made available.