The United States is facing pressure over its Cuba policy at the annual meeting of the Organization of American States (OAS), being held in Honduras.
Most Latin American countries want the Caribbean island to return to the group, from which it was expelled in 1962, without preconditions.
But US Secretary of State Hillary Clinton said Cuba should only return if it passed democratic reforms.
Mrs Clinton said no consensus had been reached on the first day of the summit.
Cuba, which was expelled from OAS after the 1959 communist revolution, has said it will not accept membership if offered.
Cuban Foreign Ministry official Carlos Fernandez said reversing the expulsion would be "a good sign for the Organization of American States" but that his country had no intention of rejoining the group.
'Common way forward'
Honduran President Manuel Zelaya told leaders at the annual two-day summit that the decision to expel Cuba - following the revolution which turned the country into a one-party communist state - was "a day that will live in infamy".
He said it was "time to correct that mistake", or the 34 members of the group would be "colluding with that mindset of yesterday".
Yes, lets mock democracy in the Americas, once again, by inviting the Island (private property of the Castros) into the club, great.