Washington, March 9 (RHC-teleSUR)-- The U.S. is set to announce further measures on March 17 to relax its travel and commercial controls on Cuba, before President Barack Obama’s historic visit to the Caribbean island later in the month, U.S. congressional sources said on Tuesday.

The new rules mark a further step by Obama to normalize the more than half-century-old U.S. economic blockade against Cuba, using his executive powers to bypass the U.S. Congress.

The expected announcement will come days before Obama flies to Havana for a March 21-22 official visit.  It will be the first visit to Cuba by a sitting U.S. president since 1928.

The new rules are believed to encompass changes to make it easier for United States citizens to travel to Cuba if they qualify under 12 authorized categories of travel such as educational or cultural visits, as well as further loosen trade and banking rules, said the sources, who were briefed on the matter by administration officials.

The measures could also include revised regulations on how the U.S. dollar can be used in trade with Cuba.

But although the changes, which follow relaxed cruise rules and an exchange of embassies, will go some way to normalizing relations, Cuba has said that it is meaningless until the blockade is lifted.

In December, Cuban President Raul Castro told Cuban lawmakers: “The essential thing now is that President Barack Obama uses with determination his vast executive powers to modify the implementation of the blockade, which would give meaning to what has been achieved so far and permit for solid progress to continue.”

The U.S. blockade has cost Cuba US$117 billion.