Top diplomats from 11 nations are meeting Tuesday in London with members of the Syrian opposition to encourage those opposed to President Bashar al-Assad to attend a long-delayed peace conference with the government.
Speaking before the talks with other core members of the Friends of Syria group, British Foreign Secretary William Hague said the longer the Syrian conflict continues, "the more sectarian it becomes." He said in a local radio interview that all sides of the opposition should join the peace talks.
The opposition's many factions have made it difficult to arrange the peace talks, with questions about who would attend and under what conditions.
Opposition leaders have threatened to boycott the proposed peace conference unless President Bashar al-Assad agrees to step down. Mr. Assad insists he will remain in office until his term ends in 2014, and possibly seek re-election as well.
U.S. Secretary of State John Kerry has been working with Russian Foreign Minister Sergei Lavrov and U.N.-Arab League envoy Lakhdar Brahimi to arrange the meeting in Geneva, with a goal of allowing the Syrian sides to negotiate a political solution.
Kerry said Monday there can be no peaceful solution as long as Mr. Assad remains in power.
"Now I don't know anyone who believes the opposition will ever consent to Bashar al-Assad being part of that [transitional] government. And if he [Bashar al-Assad] thinks he's going to solve problems by running for re-election I can say to him, I think with certainty, this war will not end as long as that's the case or he [Assad] is there."
Officials have given conflicting signals in the past week about whether a date for the talks has been set. U.S. officials say they hope the conference can take place as soon as late November.
Setting a date will likely be up to Brahimi and the United Nations. He gave a somber assessment of the situation in Syria during a stop in Baghdad Monday.
''The Syrian crisis is too serious and dangerous not only for the Syrian people but the region and world alike. I think all people, who are concerned with the affairs of the region, have unanimously agreed that the Syrian crisis is the most serious one in the world and it threatens world peace and stability. In fact, the international community is too late to offer help to the Syrian people.''
Tuesday's meeting in London will bring together officials from Britain, Egypt, France, Germany, Italy, Jordan, Qatar, Saudi Arabia, Turkey, the United States and the United Arab Emirates.
The fighting in Syria has killed more than 100,000 people and forced millions from their homes since March 2011.