U.N.-U.S. Pressure on Syria as SNC Urges World to Prevent Chemical Arms 'Disaster'

The world must act to stop President Bashar Assad's regime unleashing a chemical weapon "disaster", opposition Syrian National Council chief George Sabra said on Friday, as U.N. chief Ban Ki-moon said any use of chemical arms would be an "outrageous crime."

"We ask the countries of the world to act before disaster hits not after," Sabra said.

"The Syrian people will neither forget nor forgive anyone who orders the use of weapons of mass destruction, or anyone who is complicit in the crime, or anyone who moves only after the crime is committed," he added.

His comments, aired by satellite news channel Al-Jazeera, came amid mounting international warnings to Assad's regime not to use chemical weapons to suppress the rebellion.

The Syrian government has insisted that it would never resort to chemical weapons.

"We ask for deeds, not just words. We want action, not warnings," Sabra said.

"The danger does not only threaten just Syria and its neighbors, but will also have a negative impact on global security," he said.

Sabra called on Assad's remaining troops to defect to the rebels.

"Do not obey the orders of the tyrant," he said.

"We call on troops and members of the security forces, and tell them that Syria, the country and its people, are more important than anything else."

Meanwhile, the U.N.'s secretary general warned that any use of chemical weapons by Assad to combat the revolt would be an "outrageous crime".

"If it is the case, then it will be an outrageous crime in the name of humanity," Ban told a news conference after visiting a Syrian refugee camp in the Turkish border town of Islahiye.

He said "alarming news that the Syrian government has been preparing to use chemical weapons" was being received, adding however that none of the reports had been confirmed.

The U.N. chief, who flew to Turkey after visiting Jordan early Friday, repeated that he had written a letter to Assad urging him "not to use under any circumstances chemical weapons" and warning him that "it will create huge consequences."

The United States says the use of chemical weapons in Syria is a red line for Washington and fears that battlefield advances by Syrian rebels could prompt the regime to use chemical arms, or such stocks could turn up in the hands of groups hostile to the United States and its allies.

On Monday, U.S. President Barack Obama warned Assad of "consequences" if he used chemical weapons against his own people.

Ban's visit also comes a day after three-way talks between U.S. Secretary of State Hillary Clinton, her Russian counterpart Sergei Lavrov and U.N. peace envoy to Syria Lakhdar Brahimi ended without any "sensational decisions".

Clinton called Friday on all parties with influence in Syria to make a "concerted push" together to halt the conflict.

Clinton said there had been no "great breakthrough" during talks with Lavrov and Brahimi, but noted there would be further meetings.

"All of us with any influence on the process, with any influence on the regime or the opposition, needs to be engaged with Brahimi for a concerted, sincere push to see what is possible", Clinton said.

Brahimi said all three agreed the situation was very bad in Syria during the surprise talks on the sidelines of an international gathering in Dublin.

Ban on Friday urged the international community not to "close your eyes while people are suffering" and stand united to end the crisis.

"I appeal to all sides particularly the Syrian government -- stop the killing. Stop the violence in the name of humanity," Ban told reporters.

"And I urge the international community and in particular the Security Council to stand united and act decisively to end the crisis."

Russia and China have blocked resolutions in the Security Council designed to put pressure on the Assad regime.

"No one should have any illusions about how hard this remains," Clinton said during a visit to Northern Ireland.

Recent developments in Syria were "increasingly dangerous, not only to Syrians but to their neighbors," she added.

Clinton said she and the Russians would be sending officials for talks with Brahimi in the next few days to "talk about how we can operationalize the path forward."