Havana (CNN) -- A U.S. congressional delegation met with Cuban President Raul Castro, but ended a two-day visit to Havana without securing the release of an American contractor.
Sen. Patrick Leahy, chairman of the Senate Judiciary Committee, said on Wednesday that efforts to win freedom for Alan Gross will take more time.
"I wish he could be released," Leahy told CNN shortly before leaving for the airport. "I think the point has been made. Obviously it will take more negotiations. The man is not a spy. He should go home."
Gross is serving a 15-year sentence for bringing in banned communications equipment to Cuba. He has been held since 2009.
Gross had said his work was meant to connect the island's small Jewish community to the internet. Cuban officials, however, said he was part of a covert U.S. program to destabilize the government.
Leahy and Chris Van Hollen, a Democrat from Gross's home state of Maryland, met him at a military hospital in Havana where he is serving his sentence.
Gross's family and attorneys have said he has chronic health problems. Cuban officials say he is healthy.
The lawmakers did not comment on his condition.
In addition to meeting with Raul Castro, the delegation also spoke with Foreign Minister Bruno Rodriguez Parilla.
Leahy made a similar trip last year.
Cuban officials have called for talks with the United States about releasing five Cuban intelligence agents sentenced to long prison terms.
The State Department has rejected the notion of any prisoner swap.
Cuba also has also argued for the United States to lift a long-standing trade embargo.
Leahy told CNN on Wednesday that the United States and Cuba needed to move away from their Cold War-era stand-off.
"I think everyone realizes that this is not the 1960's," he said. "This is a different century, a different world. We have to adapt to it. Not to change their government or they to change ours."
Leahy said the delegation, one of the largest in years to visit Cuba, would discuss the matter with the White House when the group returns to Washington.
The Obama administration has also pressed Havana to release Gross.
Gross's family has sued the company he worked for and the U.S. government for sending him to Cuba without warning him about the possible consequences of arrest.
The congressional delegation also included Democratic Sens Sherrod Brown of Ohio, Sheldon Whitehouse of Rhode Island, and Debbie Stabenow of Michigan as well as Sen. Jeff Flake, a Republican of Arizona.
Democratic Rep. Jim McGovern of Massachusetts also made the trip. The delegation was next headed to Haiti.
The trip comes with Congress on a week's recess.