MIAMI — Passengers set sail Sunday from Miami on an historic cruise to Cuba, the first in decades to depart from a U.S. seaport for the island nation.

Carnival’s 704-passenger Adonia left port at 4:24 p.m., bound for Havana. Carnival’s Cuba cruises, operating under its Fathom brand, will also visit the ports of Cienfuegos and Santiago de Cuba on the seven-day outing. Several Cuba-born passengers, among hundreds of others, were aboard, it said.

The cruise comes after Cuba loosened its policy banning Cuban-born people from arriving to the country by sea, a rule that threatened to stop the cruises from happening.

Restarting the cruises was an important element of a bid by President Barack Obama’s administration’s to increase tourism to Cuba after the Dec. 17, 2014, decision to restore diplomatic relations and move toward normalization.

The most recent such cruise was in 1978.

When it first announced the cruises, Carnival said it would bar Cuban-born passengers due to the government’s policy. But the Cuban-American community in Miami complained and filed a discrimination lawsuit in response. After that, the company said it would only sail to Cuba if the policy changed, which Cuba did on April 22.