Three Cuban intelligence agents who had served 16 years in U.S. jails returned to Cuba on Wednesday as part of a prisoner exchange in which Havana freed an American foreign aid worker, President Raul Castro said.

"Gerardo, Ramon and Antonio arrived in our homeland today," he said of the three remaining "antiterrorist heroes" known mostly by their first names. They are Gerardo Hernandez, 49, Ramon Labañino, 51, and Antonio Guerrero, 56.

Castro said he spoke with U.S. President Barack Obama by telephone on Tuesday ahead of Obama's announcement that the United States would change its Cuba policy and seek to normalize relations between the longtime adversaries.

U.S. aid worker Alan Gross, who had served five years in a Cuban prison, was released.

The release of the three remaining Cuban agents will likely be hailed as resounding victory at home for Castro, but he avoided triumphal statements in his televised address.

He said it was a cause for joy for "enormous joy of their families and our all of our people."

In a rare nod to the United States following nearly 56 years of hostilities between the two countries, Castro praised Obama.

"This decision by President Obama deserves respect and recognition by our people," Castro said.