Saudi Arabia's Foreign Minister Abdel Al-Jubeir has issued a fresh call for Syrian President Bashar al-Assad to step down through negotiations or else be forcibly removed from power, as Syrian opposition groups held talks in the Saudi capital Riyadh.

Jubeir made the statement on Thursday, while Syrian opposition leaders discussed forming a unified front before proposed peace talks with Assad's government in Vienna. 

The Saudi foreign minister said that he hoped the Syrian opposition could come up with a common vision for Syria during the meeting. He urged delegates to prove wrong those who argue that the Syrian opposition is too fragmented to present a unified front at future peace talks.

His comments were echoed by Gulf leaders meeting for the annual Gulf Cooperation Council (GCC) summit in the Saudi capital.

The leaders of the GCC - comprising Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates - said that they "support a political settlement ... that guarantees the territorial integrity and independence of Syria" as their two-day meeting came to an end on Thursday.

Meanwhile, the Syrian opposition figures in Riyadh agreed to set up a body including political and armed factions to lead preparations for the talks with the Syrian government.

They have chosen a new secretary general and a new spokesman, as well as the formation of a supreme commission for negotiation that comprised 23 members.

Monzer Akbik of the Syrian National Coalition, speaking from Dubai where he was in contact with delegates in Saudi Arabia, said the group would include six from the coalition in exile, six from rebel factions, five from a Damascus-based opposition group and eight independent figures.

"They are going to be the decision-makers in terms of the political settlement," Akbik told Reuters news agency, adding that a separate negotiating team of 15 members would also be appointed.

Marwan Kabalan, a Syrian political analyst, told Al Jazeera that the two-day summit in Riyadh was very significant because most of the GCC states were either directly or indirectly involved in the Syrian conflict.

He said that the Syrian opposition "are closer to a united political vision for road map to peace in Syria".

The GCC has endorsed a political solution for the Syria conflict, under an international framework agreed to last month.

The Gulf states said that they back the Vienna agreement, which was made last month and set a January 1 target for peace talks and would see a transitional government set up in six months and elections in 18 months.

Source: Al Jazeera and agencies