HAVANA (REUTERS) - The first US cruise ship to arrive in Cuba in decades received a warm welcome on Monday from Havana residents who gathered at the wharf in the colonial old city as hundreds of Americans waved from the decks of the vessel.

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 just weeks after Obama's visit to the Caribbean island.

Carnival Corp's Adonia, a small ship with a capacity of 700 passengers, slipped through the channel into Havana Bay in the morning under picture-perfect skies, then docked at the colonial old town recently visited by Obama.

A Cuban law prohibiting nationals from entering the country by sea had almost delayed the cruise but was lifted by local authorities just over a week ago.

Obama has made the dramatic shift in US policy toward Cuba a part of his legacy.

The two countries reestablished diplomatic relations a year ago and have signed agreements on issues of common concern such as the environment, postal services and direct flights.

Talks are ongoing over other issues that have kept the next-door neighbours apart, from the return of fugitives to reparations for embargo damages and the return of the Guantanamo Naval Base.

Obama had urged the Republican-controlled Congress to lift the trade embargo and travel ban, but to no avail, resorting to his executive powers to punch holes in them instead.

Both sides appear determined to make further progress on travel before Obama leaves office.

John Kavulich, president of the New York-based US-Cuba Trade and Economic Council, said: "Regularly scheduled cruises are the third leg of the land, sea and air efforts by the Obama Administration to cement its policy changes, the goal is to make the initiatives big and loud so that they are harder to dislodge."