Russia and China on Thursday used their veto as permanent members of the UN Security Council for the third time to block a resolution on Syria.

A timeline of action by the 15-nation council on Syria:

Aug 3, 2011: Five months into the uprising against President Bashar al-Assad, the UN Security Council makes its first pronouncement on Syria with a statement condemning deadly attacks on civilians and calling on those responsible to be held “accountable.” But as it is not a formal resolution no concrete action can be taken. The council says Assad must carry out promised reforms. The estimated Syria death toll is 1,600.

Oct 5, 2011: After nearly six months of negotiations on a resolution, Russia and China use their veto for the first time on Syria when Britain, France, Germany and Portugal propose possible measures unless Assad ends his assault on demonstrators which at this stage had left 2,700 dead. Nine of the 15-member council voted for, Russia and China vote against, South Africa, India, Brazil and Lebanon abstained. It was the first joint Russian-China veto since they blocked UN sanctions against Zimbabwe’s President Robert Mugabe in July 2008.

Feb 4, 2012: At a special Saturday meeting of the council, Russia and China wield their veto for a second time, this time on a resolution condemning the Syrian government’s crackdown. The United States calls the move “shameful”. India and South which abstained in the first vote back this resolution. The Syrian opposition says more than 6,000 have been killed in the uprising against Assad.

April 14, 2012: With Kofi Annan installed as UN-Arab League peace envoy, the Security Council unanimously agreed in Resolution 2042 to send an advance party of 30 unarmed ceasefire monitors to Syria. Russia and China insist that any demands made to the Syrian government must also apply to the opposition.

The resolution called upon the Syrian government to “implement visibly” all commitments under Annan’s peace plan — including the withdrawal of all troops and heavy guns from Syrian cities. The UN says more than 9,000 have been killed in Syria, monitors give a figure of more than 10,000.

April 21, 2012: The Security Council unanimously passes Resolution 2043 allowing the ceasefire monitoring mission to be increased to 300 despite the strong doubts of many Western nations.

The observers were sent for an initial period of 90 days. The United States says it cannot rule out blocking an extension of the mission. The UN says it can no longer give an accurate estimate for the dead. Syrian activists say the toll is over 11,000.

July 19, 2012: Russia and China veto for a third time. This time Britain, France, United States, Germany and Portugal want sanctions added to a resolution which would renew the UN Supervision Mission in Syria.

Rejecting sanctions against its ally, Russia says the west is seeking “military intervention” in Syria. Eleven countries voted in favor, Russia and China against, South Africa and Pakistan abstained. Activists say more than 17,000 have died in Syria.