In an interview, a State Department official described the pressure building for a new policy toward Cuba as a “steamroller” and said that the administration was “trying to drive it, rather than get run over by it.”

The official said any overtures toward Cuba would be made cautiously, allowing Mr. Obama to walk a fine line between those who want to end the embargo and those who see any engagement with Cuba as making concessions to a dictatorship. The official said that the administration also wanted to be careful to make it clear that its openness to engagement with Cuba did not mean the United States would turn a blind eye to the Cuban government’s poor record on human rights.

Experts on Cuba said there were good reasons for Mr. Obama’s caution. Among them is that the president has a full legislative agenda and does not want opposition by anti-Castro conservatives to interfere with more pressing concerns. The experts added that it was almost impossible to predict Havana’s next move and that the Cuban government had a history of shutting the door each time there was any serious move toward improving relations. Indeed, after the recent Latin American summit meeting, Fidel Castro said that Mr. Obama had misinterpreted comments by President Raúl Castro, his brother, that “everything” would be up for discussion.

Carl E. Meacham, who is a senior foreign policy adviser to Senator Richard G. Lugar, Republican of Indiana, and who wrote a report critical of the United States’ embargo, said: “We in Washington have to focus on our own objectives, and not on events in Havana. What we’re doing is threatening to President Castro, and there will be reaction. But we have to keep moving forward.”

The Obama administration has indicated that it would like the Cuban government to stop charging fees on remittances sent to the island, open Cuba to American telecommunications companies and release all political prisoners.

But another State Department official, echoing Mr. Meacham, said the United States would not delay its own efforts while waiting for Havana to make such moves.

“I don’t think we want to paint a big red line in the sand to preclude any conversations,” the official said. “We need to begin having conversations.”