Beijing (AsiaNews/ Agencies) - The "regime is collapsing [. . .]. Militarily it is crumbling as it no longer occupies more than 30 per cent of Syrian territory," said Riad Hijab, a former Syrian prime minister who fled, at a press conference in Amman, Jordan. Its fall is a matter of weeks. Morally, materially and economically, the system has imploded. The ex premier urged the opposition to set up a united front to build a new Syria, and called on the military to stop slaughtering civilians. He said he will join the rebels and wants Assad supporters to break away from the regime.

Hijab, who fled last week, is the highest ranking official from the Assad regime to defect and to call for his removal. He is not the only top official to do so. Syrian Republic Guard Brigadier General Manaf Tlass, one of Assad's top military advisers, and Nawaf al-Faes, Syrian ambassador to Iraq, have also defected.

Hijab's statement comes as Syrian President's special envoy Bouthaina Shaaban met Chinese Foreign Minister Yang Jiechi in Beijing. His visit, which is meant to find a diplomatic solution to the conflict and revive the Annan plan, has also rekindled the debate over China's support for the current Syrian government, a position criticised by the European Union, the United States and the Arab League, which back the opposition, financially and otherwise.

Chinese Foreign Ministry spokesperson Qin Gang said yesterday that the meeting with Bouthaina was part of Beijing's diplomatic effort to mediate between rebels and the regime. The latter includes a future meeting with rebel representatives to negotiate an immediate ceasefire.

In 17 months of war, China and Russia have vetoed three UN Security Council's resolutions in order to prevent any anti-Assad measure from being taken.

Meanwhile, fighting continues in Aleppo as rebels claim to have shot down a Syrian fighter plane, producing footage of a man they say was the captured pilot.

Since violence broke out, some 20,000 people have died and 2 million civilians have been caught in the crossfire. About a million have been made homeless. About 140,000 Syrian refugees have crossed into Lebanon, Jordan, Turkey and Iraq.

UN humanitarian chief Valerie Amos is in Damascus today to assess ways to increase the flow of emergency aid. She is expected to ask rebels and government for a humanitarian corridor to help civilians.

She should meet Syria's new prime minister, Wail al-Halqi, Foreign Minister Walid Muallem, and his deputy Faisal Meqdad.