Gross, a Maryland-native, was imprisoned in December 2009. At the time he was working as a subcontractor on a democracy-building project funded by the U.S. Agency for International Development.
A delegation of American lawmakers led by Sen. Patrick Leahy arrived in Cuba on Monday to gauge the island's economic changes and stress the importance of freeing a jailed American whose detention has chilled relations between the two countries.
The trip, which included five senators, was the first to the Communist-run island by high-level U.S. politicians since President Barack Obama's re-election in November.
It comes a year after another group of legislators led by Leahy, a Vermont Democrat, came to Cuba and met with President Raul Castro. Last year's delegation also visited Alan Gross, an American jailed since 2009 for illegally distributing communications equipment on the island while on a U.S.-funded democracy-building program.
In their meetings, the lawmakers will stress that freeing Gross, who is serving a 15-year sentence, is a crucial prerequisite for improved ties, a State Department official told The Associated Press. The official spoke on condition of anonymity, lacking authorization to comment publicly.
"Nothing would make me happier if, when we leave in a couple of days, for Alan Gross to be on the plane with us," Leahy said following the group's arrival, before adding: "I don't think that is likely to happen."
Leahy said the aim of the trip is to work toward better relations between the two countries, and that both sides would have to give ground. He said many Americans agree U.S. policy in place for decades has become anachronistic.
"There is a growing sense by many in the U.S. who do not have a Cold War attitude that they would like to see a change," he said. The United States has maintained an economic embargo on the island for 51 years, since shortly after Fidel Castro came to power.
Rep. Jim McGovern, a Massachusetts Democrat, said the lawmakers would "like to see relations improve," adding that he hoped to see the day when all U.S. citizens could travel to Cuba freely. Washington bars American tourism to the island, though the number of U.S. citizens traveling to Cuba on licensed cultural, religious or educational exchanges has soared under new guidelines enacted by the Obama administration.
The lawmakers also hope to get a firsthand look at economic changes on the island instituted by Castro in recent years, including the legalization of limited private enterprise, the creation of a real estate market and the elimination of travel restrictions for most islanders.
The delegation also includes Sens. Jeff Flake, R-Arizona; Sherrod Brown, D-Ohio; Debbie Stabenow, D-Michigan; and Sheldon Whitehouse, D-Rhode Island, along with McGovern and Rep. Chris Van Hollen of Maryland, Gross's home state.
The group arrived Monday and is scheduled to depart early Wednesday. The declined to make public details of their agenda, including whether they would meet with Castro or Gross.
Cuba has said it is willing to consider releasing the 63-year-old, but in return wants Washington to negotiate the fate of five Cuban intelligence agents sentenced to long jail terms in the United States.
Washington has said publicly that a swap is not in the cards.