LONDON (AP) — The U.S. is frantically trying to salvage a Syrian opposition conference set for this coming week that John Kerry plans to attend during his first official overseas trip as U.S. secretary of state.

A senior Obama administration official said Sunday that Kerry has sent his top Syrian envoy to Cairo in hopes of convincing opposition leaders that the Rome conference will be critical to securing additional aid from the United States and Europe.

Some members of the sharply divided Syrian Opposition Council are threatening to boycott Wednesday's meeting.