The US government is optimistic about the prospects of reaching an agreement with Cuba to reopen embassies before April’s Summit of the Americas in Panama, Washington’s chief negotiator in talks with Havana said.

“I do think we can get this done in time for the Summit of the Americas,” Assistant Secretary of State Roberta Jacobson said Friday after discussions in Washington with a Cuban delegation.

The gathering in Panama could be the occasion for the first meeting between President Barack Obama and Cuba’s Raul Castro since the two men announced in December an agreement to restore bilateral diplomatic ties after a break of more than 50 years.

Friday’s talks at the State Department were “productive and encouraging”, Jacobson told reporters after her second encounter with Havana’s representative, veteran diplomat Josefina Vidal.

Cuba moved Friday to eliminate one obstacle to an early reopening of embassies, as Vidal said Havana was not making its removal from the US list of state sponsors of terrorism a precondition for progress toward normalisation.

Even so, she suggested the removal was needed before the formal restoration of diplomatic relations.

“It would be very difficult to explain that Cuba and the United States have established normal diplomatic relations when Cuba is kept on this list,” Vidal said.

Secretary of State John Kerry said earlier Friday that the issue of the list was not on the agenda for the discussions between Jacobson and Vidal.

“The state-sponsored terrorism designation is a separate process, it is not a negotiation. And that evaluation will be made appropriately and nothing will be done with respect to the list until the evaluation is completed,” Kerry said.

The process of removing a country from the list requires a formal notification from the president to Congress, which then has 45 days to consider the matter.