WASHINGTON -- In the most sweeping change in US-Cuban relations in five decades, US President Barack Obama announced on Wednesday plans to normalize ties with Cuba in a move that has sparked much controversy in the United States.

"Neither the American or the Cuban people are well served by a policy that's rooted in events that took place before many of us were born," Obama said in a televised speech on Wednesday.

"We will end an outdated approach that for decades has failed to advance our interests and, instead, we will begin to normalize relations between our two countries," Obama said.

The US severed ties with Cuba in 1961, shortly after Cuban leader Fidel Castro launched a revolution that toppled a US- friendly government. The two countries have been at loggerheads ever since, with tensions boiling over on a number of occasions, most notably the Cuban Missile Crisis and the Bay of Pigs Invasion.

Emotions are running high on the issue, with many applauding the move but many others, such as Republicans and a few Democrats, slamming the decision.

Marco Rubio, a son of Cuban immigrants and incoming Republican chairman of the Senate Foreign Relations Subcommittee on the Western Hemisphere, said he will "make every effort to block this dangerous and desperate attempt by the president to burnish his legacy at the Cuban people's expense."

He slammed the decision as not only "naive" but also "willfully ignorant" in a speech on Wednesday broadcast by a number of US media.

Ted Cruz, a Republican Senator whose father hails from Cuba, said on Fox News that Obama's plan to normalize relations with Cuba was a "tragic mistake".

Democratic Senator Robert Menendez, a son of Cuban immigrants and Chairman of the Senate Foreign Relations Committee, also blasted the Obama administration, calling the decision "misguided" and lambasting Obama over the exchange of three Cuban spies for a US intelligence asset.

Among analysts, some believe it is time for a normalization of relations while others contend the Castro government needs to make changes.

"Obama is normalizing relations with Cuba because the US sanctions have been a complete failure. The President hopes that he can produce better results through bargaining and negotiation," Brookings Institution's senior fellow Darrell West told Xinhua, adding that Obama is shifting his focus to foreign policy in the last two years of his time in office.

But some analysts believe the US-Cuba normalization will hit a number of roadblocks.

Heritage Foundation's senior fellow Mike Gonzalez said in a conference call for journalists that the incoming Republican- controlled Congress will react to stop the president from implementing the sweeping changes, adding that Congress has a number of tools at its disposal.

"(Congress) can put a hold on whatever ambassador is appointed (to serve in Cuba), it can...prevent funds from being spent on an embassy," he said, citing examples.

In the same call, Heritage Foundation's research associate Ana Rosa Quintana said the recent Republican sweep in the midterm elections showed that Americans are not happy with Obama's foreign policy.

She contended that the Helms-Burton Act, which tightened the trade embargo against Cuba and ratcheted up restrictions on Americans traveling to the country, is unlikely to be repealed by the incoming Republican-controlled Congress.

As such, Obama will use executive authority to relax some restrictions on banking, certain trade and travel to Cuba.

US Treasury Secretary Jacob Lew said Wednesday in a statement that enhanced contact with the US is "key to advancing political and economic freedom for the Cuban people."

"The steps we are taking will increase travel, commerce, communications and private business development between the United States and Cuba and promote positive change for Cuba's citizens" Lew said.