Syrian President Bashar al-Assad will be "squandering his last chance" if he fails to comply with a peace plan brokered by international envoy Kofi Annan, dpa quoted US Secretary of State Hillary Rodham Clinton as warning on Wednesday. Her comments on the sidelines of a NATO foreign ministers' meeting in Brussels came amid reports from Syria that government forces had shelled dissident areas in violation of the ceasefire dictated by the Annan plan. Activists said at least 12 people were killed. "It is obviously quite concerning that while we are deploying (UN) monitors ... the guns of the al-Assad regime are once again firing in Homs, Idlib and elsewhere and Syrians continue to die," Clinton said. "We are certainly cognizant of the very challenging road ahead." "We are at a crucial turning point ... We will judge the al-Assad regime by their actions, not their words," she added. "Either we succeed in pushing forward with Kofi Annan's plan ... or we see al-Assad squandering his last chance before additional measures will have to be considered. We will continue to increase the pressure."