SAN SALVADOR, El Salvador — Cuba has agreed to restart talks with the United States on immigration and has signaled its willingness to cooperate on issues including terrorism, drug trafficking and even mail service, a sign that the island's communist government is warming to President Obama's call for a new relationship after decades of tension, U.S. officials said yesterday.

The breakthrough was announced as Secretary of State Hillary Rodham Clinton began a three-day trip to Latin America, where she is expected to face pressure from regional leaders to take further steps to ease the U.S. policy of isolating Cuba.

A senior State Department official, who spoke on condition of anonymity, called the Cuban moves "a very positive development" that indicated the country's rulers want better relations. "It's our hope this will be understood in the region in a positive way," he said.

No date was set for the start of the talks.

Obama has promised a "new beginning" with Cuba, and his overtures have included lifting restrictions on visits by Cuban-Americans to the island and allowing U.S. telecommunications firms to operate there. But the administration has moved cautiously, mindful of domestic political repercussions. Obama and Clinton have said the U.S. will not lift its economic embargo until President Raul Castro's government makes democratic reforms.

The announcement of the talks could take the edge off what was shaping up as a battle over Cuba at a regional meeting of foreign ministers that Clinton is scheduled to attend tomorrow in Honduras. The ministers have been considering readmitting Cuba into the Organization of American States, the main forum for political cooperation in the hemisphere, for the first time since 1962.

The United States has resisted readmitting Cuba, arguing it would violate the OAS charter on democratic principles. But the idea has widespread support in Latin America.