Cuba's Fidel Castro met this weekend with the three intelligence agents freed by the United States as part of last December's historic rapprochement, state media said Monday.

In a letter published in several state newspapers, the 88-year-old father of the Cuban Revolution said he had hosted the men at his home in Havana on Saturday, "73 days after they set foot back on Cuban soil."

The United States and Cuba said they made progress Friday in talks on restoring diplomatic ties and Washington could reopen its Havana embassy before a key April summit if differences are overcome.

After a second round of historic meetings, negotiators from both countries appeared optimistic about the road ahead, but cautioned there were still outstanding issues to resolve in order to restore diplomatic ties frozen for half a century.

The United States rebuffed a Cuban demand to be taken off the U.S. list of state sponsors of terror Friday as they opened a second round of historic talks to restore long severed diplomatic ties.

U.S. Secretary of State John Kerry said the terror designation, in place since 1982, would be reviewed separately but was not a matter for negotiation.

American socialite Paris Hilton is visiting Cuba, an island on which her family lost a hotel half a century ago after Fidel Castro came to power.

The hotel heiress posted a photograph of herself in Havana with the caption "Cuba baby!"

Spain's conservative government reacted angrily Thursday to a visit by former Socialist Prime Minister Jose Luis Rodriguez Zapatero to Cuba and his meeting with Cuban President Raul Castro, calling it disloyal.

Zapatero, Spain's prime minister between 2004 and 2011, and his foreign minister at the time, Miguel Angel Moratinos, met with Castro on Wednesday during a private visit to the Communist-run island.

Former U.N. secretary-general Kofi Annan arrives in Cuba on Thursday to help prod negotiators from the Colombian government and leftist guerrillas to clinch a peace agreement.

The 2001 Nobel Peace Prize winner will meet with both delegations, after declaring in Colombia that any peace agreement must be just, and must meet the standards of the international community.

Just two days ahead of a second round of talks on restoring diplomatic ties frozen for five decades, Cuba and the United States on Wednesday staked out competing demands to ensure progress.

Cuban officials demanded that as a preliminary step to renewing relations, Washington must remove the island from its list of state sponsors of terrorism.

Colombia's government and leftist rebels launched a new round of peace talks Wednesday, one day ahead of the arrival of former U.N. Secretary General Kofi Annan to help facilitate negotiations.

The talks between the government and the Revolutionary Armed Forces of Colombia (FARC), now into their third year, are resuming after a two-week hiatus.

Russia is seeking backing from Abu Dhabi investors to build a giant airport in Cuba seen as an international gateway to Latin America, a report said Wednesday.

Talks on the proposal have been held between Moscow and Abu Dhabi state investment fund Mubadala, The National newspaper reported citing Russian Industry Minister Denis Manturov.

Communist Cuba's revolution has held sway for so long -- 56 years -- that those who remember no other system are nearing retirement age with a mixture of fond memories, and just a few regrets.

"We were part of a generation that changed everything, romantic, contradictory, and maybe one of a kind," journalist and author Manuel Juan Somoza, 69, told Agence France Presse.