Egyptian President Mohamed Mursi urged world powers not to hesitate to enforce a no-fly zone over Syria.
The Islamist head of state had previously appeared somewhat less confrontational toward President Bashar al-Assad than Saudi Arabia and other Gulf states.
But in a speech to Sunni Muslim clerics in Cairo he said he had cut all ties to Damascus and demanded Lebanon's Shi'ite Hezbollah movement quit Syria.
US President Barack Obama has tip-toed over the 'red-line' and armed Syrian rebels but it is a gamble of huge proportions.
Writing for ITV News, international affairs analyst David Butter looks at the timing of US support for Syria and when it may arrive.
Are the US supplied assault rifles too little, too late and what incentive is there for Assad to enter peace talks?