Iran and its Shiite Lebanese ally Hizbullah are “propping up” President Bashar al-Assad and providing him with increasing support, British Foreign Secretary William Hague said on Wednesday.

Britain would urge international powers to set a date in the next few days for an international conference to try to end the two-year-old conflict engulfing Syria and threatening regional stability, Hague said at a meeting in Amman of the Friends of Syria alliance.

“It is the longstanding view of the UK that Assad needs to go, and we have never been able to see any solution which involves him staying,” Hague said, according to the AFP news agency.

The aim of the meeting would be agreement on the formation of “a transitional government with full executive authority, formed on the basis of mutual consent,” he said.

Delegates from Britain, Egypt, France, Germany, Italy, Jordan, Qatar, Saudi Arabia, Turkey, the United Arab Emirates and the United States, are also attending the meeting.

“This meeting … in Amman is to bring together all of the key players in the region as well as the key partners in Europe and the United States to talk about strategy,” a senior US State Department official told AFP.

“It’s basically to review where we are on Syria.”