Alan Gross: How His Release Went Down

PHOTO: "@JohnKerry embraces #AlanGross at Joint Base Andrews," Dec. 17, 2014.Playjzuckman/Twitter
WATCH US and Cuba Begin Attempts to Normalize Relations

Early this morning, Alan Gross lifted off on an official U.S. transport plane and landed just a few hours later on American soil for the first time since being imprisoned in Cuba five years ago.

The agreement was reached following more than a year of secret back channel talks at the highest levels of both governments. President Obama authorized high level channels of communication with the Cuban government last spring, a senior administration official told reporters today.

There were multiple meetings with Cuban officials that took place in other countries. Canada hosted the majority of these meetings and even the Vatican played a role. Pope Francis personally issued an appeal to both Castro and Obama, calling on them to resolve the imprisonment of Gross and the three Cubans in the U.S.

“I want to thank his holiness Pope Francis,” President Obama said today in an address to the nation.

The Pope’s personal involvement was very important to the president, the senior administration official said. Obama and Pope Francis discussed Cuba when they met at the Vatican earlier this year.

The first face-to-face discussions between the U.S. and Cuba took place in June 2013 in Canada. The prison transfer that led to Gross’s release was finalized at a meeting at the Vatican this fall. No meetings took place in Cuba or the U.S.

As part of the swap, the United States agreed to the release of three Cuban agents convicted of espionage in a controversial trial that found them guilty of spying on anti-Castro groups in Miami, but not the U.S. government. In addition to Gross, Cuba also released a “U.S. intelligence asset” who has been imprisoned for nearly 20 years. This individual, who remains unnamed, was responsible for high-level counter-intelligence for the U.S.

The “swap” was for the intelligence asset, not Gross, according to the senior administration official. The Cuban government made the additional “sovereign decision” to release 53 political prisoners whose cases the U.S. brought to their attention. The US welcomes their release.

"Yesterday I spoke with Raul Castro to finalize" the release of Gross, Obama said. The conversation was a “summing up” of the work that has been done over the past year, according to the senior administration official. They discussed issues of importance in the hemisphere, while also noting that they will have differences to come. Obama made clear his intent to maintain U.S. advocacy for human rights in Cuba.

Three U.S. lawmakers accompanied Alan Gross on the plane ride home from Cuba, according to a statement from one of the lawmakers Rep. Chris Van Hollen, D-Maryland. The two others are Sen. Jeff Flake, R-Arizona, and Sen. Patrick Leahy, D-Vermont.

In a statement today, Leahy said he visited Gross twice in Cuba.

“Tim Rieser of my staff met with him two other times and spoke with him by phone weekly over a period of many months,” the Vermont Democrat added. “From discussions with Judy Gross, I know the pain and heartache and worry that Alan's imprisonment has meant for her and for their two daughters. I met twice with President Raul Castro, with Foreign Minister Rodriquez, and with other Cuban officials about Mr. Gross. I discussed his case many times with President Obama, Secretary Kerry and other U.S. officials, and I thank them for what they have accomplished.”

Flake called it “an honor to be with Alan as he touched down on U.S. soil after more than five years in a Cuban prison. When I visited Alan last month, he expressed the hope that his ordeal might somehow lead to positive changes between the United States and Cuba. With today's significant and far-reaching announcements, I think it already has."

State Department spokesperson Jen Psaki said that Secretary of State John Kerry returned to Joint Base Andrews from his European trip shortly after Alan Gross, and met briefly with him and his family in an unplanned meeting.

ABC’s Ali Weinberg contributed to this report.

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download the ABC News app for iPhone here or the ABC News app for Android here. To be notified about our live weekend digital reports, tap here.