President Obama believes Cuba has made "progress" since he moved to open relations with the communist nation in late 2014, White House spokesman Josh Earnest said Monday.

"After five decades of not seeing any results, the president felt it was time to see something different," Earnest said of Obama's Cuba policy, which has drawn sharp condemnation from many Republicans, including President-elect Trump, who say the shift was made without securing any concessions from the Raul Castro regime.

"We're pleased with the progress, and it certainly has benefited the American people in a tangible way," Earnest said, although he didn't cite any examples of progress in Cuba.

Obama's press secretary ripped critics of the president's Cuban policy change, claiming those who opposed it could not "make the case" that their opposition was rooted in a concern for Castro's human rights violations.

"I think it is very difficult for critics of this policy to make any sort of coherent, evidence-based argument that somehow the American people have been disadvantaged by this policy," Earnest said.

He cited the hundreds of commercial flights scheduled to depart the U.S. for Cuba in the coming months as an element of the Obama's policy that would be difficult to scale back, as Trump has suggested he would do if the Cuban government did not issue concessions to the U.S.

"Unwinding that ... is not as easy as the stroke of a pen," Earnest said.

He dismissed questions about whether Obama is satisfied with the Castro regime's efforts to restore political and economic freedom to Cuban citizens.

"There is no doubt that we would like to see the Cuban government do more," he said.

Republicans criticized Obama over the weekend after he offered condolences to the Castro family for the death of former dictator Fidel Castro without acknowledging his decades of abuses.

"Those critics of the statement are also critics of the policy, and have been scrambling to try to justify their loyalty to an obviously failed policy of isolation," Earnest said. "I think the president's statement quite clearly speaks for itself."

Sen. Marco Rubio on Sunday slammed Obama's statement as "pathetic," arguing the president should have mentioned publicly Fidel Castro's brutal track record of executing dissidents.

"There has been no effort to whitewash the history" of Fidel Castro's regime, Earnest said, claiming Obama wanted to remain "focused on the future."