DAMASCUS (AFP) - Saudi Arabia, Kuwait and Bahrain recalled their Damascus envoys as Sunnis' top authority on Monday urged an end to the crisis in Syria, increasing the regional isolation of President Bashar al-Assad. A day after the Arab League issued its first official statement on the crisis, calling for an end to the bloodshed, the head of the pan-Arab body urged Syrian authorities to engage in a "serious dialogue" with protesters seeking change. The United States said Monday it was "encouraged, heartened" by a tougher stand taken by Arab countries towards Syria's deadly crackdown on opposition protests. "We are very much encouraged, heartened by the strong statements that we've seen over the weekend by the Arab League as well as by the Gulf Cooperation Council," State Department deputy spokesman Mark Toner said. Rights activists said Syrian security forces shot dead a mother and her two children in the eastern city of Deir Ezzor, where 42 people were reported killed in an army assault on Sunday. The recalls by Riyadh, the Arab world's Sunni Muslim heavyweight, and fellow Gulf Cooperation Council (GCC) members Kuwait and Bahrain marked a major escalation of pressure on Assad. His regime's repression of a pro-democracy uprising has left at least 2,059 people dead, including almost 400 members of the security forces, according to the Britain-based Syrian Observatory for Human Rights. "Saudi Arabia announces the recall of its ambassador for consultations," King Abdullah said in a statement after Syrian security forces killed more than 50 people on Sunday. He urged Damascus to "stop the killing machine and the bloodshed... before it is too late" and called as well for "comprehensive and quick reforms." "The future of Syria lies between two options: either Syria chooses willingly to resort to reason, or faces being swept into deep chaos, God forbid," he said. Saudi political science lecturer Sadaqa Fadhel said King Abdullah's message reflected a "firm Arab and Muslim position" which could lead to further pressure. "The Saudi position is just a warning for now, but the kingdom could take tougher measures," he said. Kuwait and Bahrain also recalled their envoys from Damascus. "No one can accept the bloodshed in Syria... The military option must be halted," Kuwait's Foreign Minister Sheikh Mohammad al-Sabah told reporters. Bahrain's Foreign Minister, Sheikh Khaled bin Ahmad al-Khalifa, said in a brief statement on Twitter: "Bahrain is recalling its ambassador in Damascus for consultation, and has called for a resort to reason." The European Union was meanwhile mulling new sanctions against individuals and business linked to the clampdown, EU diplomats said on Monday, while Germany warned that Assad will forfeit legitimacy if his regime continues the deadly crackdown. "If President Assad maintains his refusal to engage in dialogue with the Syrian people and continues to resort to violence, the German government will consider he has forfeited his legitimacy in further overseeing the fate of his country," deputy govt spokesman Christoph Steegmans said. Meanwhile, Syrian President Bashar al-Assad on Monday appointed a new defence minister, state television reported, amid mounting Arab condemnation of nearly five months of deadly crackdown on dissent. "President Assad has signed a decree naming General Daood Rajha as the head of the defence ministry," the television report said. The 64-year-old Rajha, who was the army's chief of staff, replaces General Ali Habib who had been defence minister since 2009. Meanwhile, the website of Syria's Ministry of Defense was offline on Monday after being defaced by the "hacktivist" group Anonymous to protest a bloody crackdown on anti-government protestors. Repeated attempts to connect to the site, www.mod.gov.sy, were met with an error message on Monday.