BEIRUT (Reuters/AFP) - Syria's ambassador to Iraq defected on Wednesday in protest at the military crackdown by President Bashar al-Assad's forces against a 16-month uprising, Syrian opposition sources said.Nawaf al-Fares, who has close ties to Syrian security, would be the first senior diplomat to quit the embattled government. There has been no comment from Damascus or Baghdad.A veteran of Assad's rule who held senior positions under the late president Hafez al-Assad, Fares is from Deir al-Zor, the eastern city on the road to Iraq which has been the scene of a ferocious military onslaught by Assad forces."This is just the beginning of a series of defections on the diplomatic level. We are in touch with several ambassadors," said Mohamed Sermini, a member of the main opposition umbrella group, the Syrian National Council.The defection of Fares could be a major blow to Assad, who wants to convince a sceptical world that he is conducting a legitimate defence of his country against foreign-backed armed groups bent on toppling the government.China on Wednesday threw its weight behind UN envoy Kofi Annan, backing his call to include Assad's ally Iran in internationally brokered talks to resolve the Syrian crisis, in the face of strong Western opposition."China believes that the appropriate resolution of the Syria issue cannot be separated from the countries in the region, especially the support and participation of those countries that are influential on relevant sides in Syria," Foreign Ministry spokesman Liu Weimin said in Beijing.In Moscow, Russia resisted calls from the Syrian National Council to make Assad's resignation a condition for talks on a political transition. Talks ended in discord as an opposition leader said Moscow's policies were helping to prolong the bloodshed. "The Syrian people don't understand Russia's position. How can Russia keep supplying arms? How can they keep vetoing resolutions? There needs to be an end to mass killings," said Burhan Ghalioun, former leader of the Syrian National Council.Russia vowed on Wednesday not to follow a Western arms embargo on Syria and promised new air defence systems and other military components to President Bashar al-Assad's regime. A top Russian arms export official had raised eyebrows in Western capitals earlier in the week by saying that Russia would no longer provide new weapons for Syria.Activists on Wednesday reported a new bombardment of rebel areas of Homs, a hotbed of opposition to Assad, as well as fighting in many other parts of the country. Syria's army fired live missiles on Wednesday in an exercise aiming at showcasing its ability to "destroy any enemy targets", state media reported. The tests concluded five days of war games, which analysts say are a warning to Assad's foes.Annan was due to brief the Security Council on Wednesday on the results of a lightning diplomatic shuttle this week to Damascus, Tehran and Baghdad.  Meanwhile, Western powers on the UN Security Council are poised to present a draft resolution on Syria seeking to increase pressure on President Bashar al-Assad, envoys said Wednesday. The US, Britain and France were waiting to hear a briefing from UN-Arab League envoy Kofi Annan later in the day before putting their proposals to the 15-nation council. The mandate of the UN mission in Syria, UNSMIS, ends on July 20 and Russia, Assad's main international ally, has already circulated a draft resolution which simply rolls over the mission.

Britain's UN ambassador Mark Lyall Grant said that the western powers would imminently distribute a draft resolution."Of course we have a number of drafts ready but we will consider exactly which text to circulate in the light of Mr Annan's briefing," Lyall Grant told reporters.