Britain gave firm backing to the decision of the Arab League to suspend Syria's membership until the regime ends its brutal repression of anti-Government protesters.
Foreign Secretary William Hague said the highly-symbolic escalation of pressure on President Bashar Assad demonstrated the frustration shared by countries across the world at the continued killing.
The Arab League said the suspension, due to come into force on Wednesday, could be followed up by political and economic sanctions against Damascus amid mounting violence which has claimed 250 civilian lives this year alone.
"I welcome the strong stance taken by the Arab League today," Mr Hague said in a statement.
"Its decision to suspend Syria from Arab League activity until the Syrian regime stops the repression of civilians and implements its commitments, demonstrates the frustration Arab League members feel at President Assad's continuing intransigence.
"As Syrian security forces escalate the violence on the streets of Syria, we and others across the international community share this frustration.
"We support the Arab League in its efforts to bring about an end to the killing of Syrian people. The continuing violence is deplorable and must stop. "
The suspension of a nation which see itself in the vanguard of Arab nationalism, was backed by 18 members of the Cairo-based group with Syria itself, Lebanon and Yemen voting against and Iraq abstaining.