"I think that states that have resources ought to be looking not for how little they can do but how much they can do," the top US diplomat said, the day before a series of meetings in the British capital on the stalled Middle East peace process and aid to the Palestinian territories.
She did not specify which countries could do more, but a senior State Department official, who asked not to be named, said she was referring to Kuwait, Qatar and Libya.
Rice will attend a meeting of foreign ministers and representatives of the Mideast Quartet — the United States, Russia, the United Nations and the European Union — Friday morning, which will be followed by talks on aid to the Palestinian territories.
In the afternoon, she will meet her counterparts from Britain, France, Germany, Russia and China to discuss Iran.
Rice is also scheduled to discuss Kosovo with her European counterparts, and to hold bilateral talks with British Foreign Minister David Milliband and with Quartet envoy Tony Blair.
After the meetings in London, she is due to set off for Israel and the West Bank, her 15th visit there since US President George W. Bush announced his intention to relaunch the Middle East peace process in July 2006.
Bush, who hosted a conference that formally restarted Middle East peace negotiations in November last year after a seven-year freeze, is to visit Israel, Saudi Arabia and Egypt from May 13 to 18.