Washington: The leading Republican in the US House of Representatives Wednesday slammed President Barack Obama's decision to resume full diplomatic ties with Communist-ruled Cuba as a "mindless" concession to a dictatorship.

Obama's decision to launch talks aimed at restoring full relations that were severed in 1961 has sparked outrage from House Speaker John Boehner and other Republican members of Congress, which will be entirely GOP-controlled in January.

"Relations with the Castro regime should not be revisited, let alone normalised, until the Cuban people enjoy freedom -- and not one second sooner," Boehner said in a statement issued after Obama announced the policy shift in an address Wednesday.

"There is no 'new course' here, only another in a long line of mindless concessions to a dictatorship that brutalises its people and schemes with our enemies," Boehner said.

The speaker, however, expressed "great joy and relief" at the news of the release of US government contractor Alan Gross, who had been imprisoned on the island for five years after being convicted of subversion and was released as part of the process of rapprochement.

In addition, the US freed three Cuban spies from the so-called "Group of Five" in exchange for a US intelligence agent imprisoned in Cuba for nearly 20 years.

The major policy shift, however, will not bring a swift end to the United States' longstanding economic embargo of the island, which will require congressional approval.

For his part, Florida Republican Sen. Marco Rubio, a Cuban-American, Wednesday said Obama's decision to start immediate talks with Cuba on restoring diplomatic relations was "inexplicable".

He also vowed that "this Congress is not going to lift the embargo."