Cuba sentenced a US contractor to 15 years in prison for covertly distributing laptops and cellular phones on the island -- a verdict certain to sour the communist-ruled nation's long-strained ties with the United States.
Washington swiftly decried the jailing of American Alan Gross as "another injustice" and called for his immediate release.
Cuba's Popular Provincial Tribunal found Gross responsible for "acts against the independence or territorial integrity" of the country, according to a statement read on state-run television.
Gross, 61, was working under contract for the US State Department when he was arrested in late 2009 for distributing the electronic devices to members of the communist-run island's small Jewish community.
"Today's sentencing adds another injustice to Alan Gross's ordeal," said National Security Council spokesman Tommy Vietor in Washington.
"He has already spent too many days in detention and should not spend one more. We urge the immediate release of Mr Gross so that he can return home to his wife and family," Vietor said.
In their ruling, the Tribunal considered information showing "direct participation of the US contractor in a subversive project by the United States government to try to destroy the revolution."
The Cuban statement also said that during the trial, the defendant "acknowledged that he had been used and manipulated" by the US Agency for International Development, which financed Gross's company, the statement read.
Gross, who can appeal the sentence, was originally accused of targeting universities, religious centers and ethnic groups to create "underground communications networks designed to foment provocations against the revolution."
His family was devastated, Gross's attorney said.
"At this difficult time for Alan and his family, we again call on the Cuban government to release him immediately on humanitarian grounds," said lawyer Peter Kahn.
The two-day, closed-door trial in Havana concluded March 5.
The case has chilled a brief warming in US-Cuban relations that followed President Barack Obama's taking office.
Cuba and the United States have not had full diplomatic relations since 1961.
In the trial, Gross was defended by attorney Nuris Pinero, who also represents five Cubans imprisoned in the United States for the past 12 years on espionage charges.
Cuba recognizes that the five were its agents, but said they were not spying on the United States, rather on anti-Castro groups in Miami planning violent attacks against Cuba.
Washington has rejected trading the jailed Cubans for Gross.
Secretary of State Hillary Clinton called on Cuba to release the contractor on Thursday.
"We deplore the injustice toward Alan Gross. We want him home," Clinton said in her first remarks on the case since the trial concluded.
"He needs to be home with his family immediately," Clinton told the House Appropriations Committee.
James Boomgard, head of the company employing Gross, said: "We are profoundly disappointed by today's verdict and sentence. Alan Gross has been accused of doing nothing more than giving peaceful people access to the internet, and for this he has already been unjustly imprisoned for more than a year without the benefit of due process and in violation of international law.
Gross was arrested in Havana in December 2009. President Raul Castro said he was acting as an "agent" of Washington distributing sophisticated communications equipment to opponents of the Cuban regime.
Cuban state media have aired a video, purported to have been leaked, in which a State Security expert is heard saying that Gross was building a "technological platform" for "network of mercenaries" including award-winning opposition blogger Yoani Sanchez. She has received awards from organizations including the US State Department.
Cuban-American US lawmakers also slammed the sentencing, with Ileana Ros-Lehtinen, a Florida congresswoman who chairs the US House Foreign Affairs Committee, calling it "a shameless act by a desperate regime."