Hundreds of tourists and a handful of emotional Cuban-Americans arrived on the first US cruise ship to sail to Havana in decades on Monday, spilling onto the cobbled streets of the old city where they were warmly greeted by residents.

It was another first for the two countries since US President Barack Obama and Cuban President Raul Castro announced a historic rapprochement in December 2014, and comes weeks after Obama's visit to the Caribbean island.

Carnival Corp's Adonia, a small ship carrying 700 passengers, slipped through the channel into Havana Bay in the morning under picture-perfect skies, then docked alongside the colonial quarter recently visited by Obama.