Latin American leaders say restoring relations needs to be followed by lifting trade embargo imposed 55 years ago.
Cuba is warning the US to scale back aid for Cuban dissidents if discussions to reopen embassies in Havana and Washington are to continue.
The cautionary statement came as a series of congressional hearings got under way, looking into US President Barack Obama’s new policy of restoring relations with Cuba.
The White House has already held negotiations with Cuban officials and more talks are planned for this month.
However, an economic embargo remains in place. Only the US Congress can lift it, but so far it has been unwilling to do so.
Al Jazeera’s Kimberly Halkett reports from Washington DC.