The discussions between U.S. Secretary of State John Kerry and Cuban Foreign Minister Bruno Rodriguez marked the first time the two nations' chief diplomats have met since a historic opening by President Barack Obama and his Cuban counterpart, Raul Castro, that was announced on Dec. 17 last year.

The closed-door meeting took place at a Panama City hotel on the eve of a Western Hemisphere summit where Obama and Castro will cross paths. The State Department had said earlier that Kerry and Rodriguez planned to meet on Thursday

Other regional leaders also are gathering in Panama City for the Summit of the Americas held every three years.

An earlier statement from the U.S. State Department said nothing about whether Obama may remove Cuba from the U.S. list of state sponsors of terrorism, a move that is widely expected following the rapprochement between the two countries.

But a U.S. Senate Foreign Relations Committee aide said on Thursday that the State Department had recommended that Obama remove Cuba from the list.

Obama's decision to move toward restoring diplomatic ties marks a sea change in relations since the Cuban revolution, when U.S.-backed dictator Fulgencio Batista fled the island on Jan. 1, 1959, as Fidel Castro and his revolutionaries seized control.

John Foster Dulles and Gonzalo Guell were the last U.S. and Cuban foreign ministers to hold a formal meeting, which took place in Washington, D.C., on Sept. 22, 1958, said a U.S. official who spoke on condition of anonymity.

The highest-level meeting after the revolution took place in April 1959, between then-Vice President Richard Nixon and Fidel Castro, who had become his country's prime minister in early 1959. Relations between the United States and Cuba rapidly deteriorated soon after.