But based on what he has heard from Libyans across the political spectrum, Mr. Feltman said, there is “a shared desire for a different type of Libya that is going to have to take into account a lot of political trends.”

Mr. Feltman was in Tripoli to speak with officials of the Transitional National Council, the interim government, while an advance team of diplomats began work to reopen the American Embassy. The embassy was among the many foreign outposts here that were closed in the early days of the conflict, which began in March and escalated into the most violent of the uprisings convulsing the Middle East.

While Colonel Qaddafi remains at large and his loyalists are still entrenched in his tribal hometown of Surt and a few other areas, the rebels that routed him after four decades in power have assumed control over most of the country, and many nations, including the major powers, have recognized the Transitional National Council as Libya’s legitimate authority.

Mr. Feltman said he discussed with the council the need to bring conventional and nonconventional weapons in Libya under control after the six-month conflict, in which many of Colonel Qaddafi’s troves of armaments were looted. Manpads, which are shoulder-fired antiaircraft missiles, were a particular concern, he said, but the United States is confident that Libya’s supplies of chemical weapons like mustard gas are secure. “They are where they are supposed to be,” Mr. Feltman said.