WASHINGTON - The United States authorized commercial ferry services to Cuba for the first time in more than a half-century on Tuesday, another major step in improving relations between the two countries.

In what was hailed by ferry operators as "a historical event," the US Treasury lifted a decades-old ban and at least four Florida companies said they had been licensed to launch boat services to the island.

That adds to the charter air services that had been permitted until now, focused on enabling Cuban-Americans to visit their families.

The ferries will also be allowed to carry cargo to the communist island of 11 million, which sits just 150 kilometers (90 miles) off the southern tip of Florida.

Four companies confirmed they had received licenses from the Treasury's Office of Foreign Assets Control to provide ferry travel.

"Today's action was a great step forward," Joseph Hinson, president of Miami-based United Americas Shipping Services, told AFP.

Havana Ferry Partners of Fort Lauderdale, Florida, said on its Facebook page that it too had received a Treasury license for ferry services from four Florida ports.

"This is a historical event. Thanks to President Barack Obama, to whom we are very grateful, for his leadership," the firm wrote.

Two others, United Caribbean Lines and Airline Brokers, a travel agency, said they also received licenses.

But Hinson suggested the first trip would still take some time, because other permissions were still needed from authorities in both countries.

Travel permits still needed

Whether by plane or ferry, American travelers to Cuba still have to come under one of 12 categories permitted in the landmark easing of US sanctions announced by the White House in December -- including family visits, official government business, humanitarian projects and sports gatherings.

But even under embargo restrictions, the number of Americans traveling to Cuba has surged in recent years, with many going via third countries.

And in a coincidental announcement not tied to the new Treasury rules, US airline JetBlue announced Tuesday it would begin direct charter flights to Havana from the New York City area, home to the second largest population of Cuban-Americans after Florida.

The moves come amid a landmark thaw in relations initiated by Obama on December 17, when he broke a nearly six-decade Cold War-rooted estrangement between the two countries by lifting sanctions on travel and some trade, as the first step toward normalizing relations.

In another event marking the thaw, Obama and Cuban leader Raul Castro spoke together for an hour at the 35-nation Summit of the Americas in Panama.

Obama thanked Castro for his "spirit of openness and courtesy," while Castro, addressing his fellow Latin American leaders, labelled the US president "an honest man."

A week after that event, the White House took the first step toward removing Cuba's longstanding designation as a "state sponsor of terror," which had added to the tough commercial embargo on the island since the beginning of the 1960s.

Cuba was added to the US terror list in 1982, originally designated for its support for armed revolution in Latin America.