Saudi Arabia will host a conference in mid-December aimed at unifying the Syrian opposition, Saudi-owned television station Al-Arabiya Al-Hadath said on Thursday, 19 November.

The conference comes after an international agreement to launch talks between government and opposition by 1 January.

"The Kingdom of Saudi Arabia is keen to gather the entire Syrian opposition and help them to (present) one voice and one unified position," Saudi Arabia's Ambassador to the United Nations Abdallah Al-Mouallimi told Al Arabiya television.

He said the conference would include "all shades of the opposition", including figures based inside Syria.

He declined to specify a date for the conference, but a Saudi government official said it was expected to take place on 15 December.

Syrian opposition figures were not immediately available for comment.

In Washington, US Secretary of State John Kerry said he expected a conference within two weeks or sooner to bring together the various factions of the Syrian opposition.

"And at that point, the United Nations is prepared to convene the parties in Geneva and begin the process of creating this transitional process for Syria itself," he told reporters after briefing members of the US Senate Intelligence Committee.

"The Syrians themselves will negotiate that," Kerry said, adding that the United States would be there to help and encourage the process.

"But, it's Syrians who have to resolve and decide the future of Syria itself," he added.

International talks were held in Vienna last week in which Saudi Arabia, Iran, Turkey and the five permanent members of the UN Security Council -- the United States, Britain, France, Russia and China - laid out a plan including formal talks between the government and opposition by 1 January.

Diplomatic sources said after those talks that Saudi Arabia, which backs Syria's insurgents seeking to topple Syrian President Bashar al-Assad, would hold a conference to unite the political opposition there. It was not immediately clear who will attend the conference.