The US has said it is "outraged" after Russia sentenced an ex-US marine to 16 years in a high security prison on spying charges.
Paul Whelan was arrested in Moscow in 2018 with a USB drive which security officers say contained state secrets.
Whelan says he was set up and called the trial a "sham", saying that without an interpreter, he could not even understand the proceedings.
US Secretary of State Mike Pompeo called for his immediate release.
"The United States is outraged by the decision of a Russian court today to convict US citizen Paul Whelan after a secret trial, with secret evidence, and without appropriate allowances for defence witnesses," he said.
Whelan, 50, was found guilty of receiving classified information at Moscow City Court. His lawyers said he would appeal.
Amid suggestions that Whelan could be used in a prisoner swap for high-profile Russians in US custody, a Kremlin spokesman said Whelan was not a "political prisoner".
"No, it is not possible. He was sentenced by a court decision, and the court decision says it all. He was charged and the charges were then proven in court and accepted by the court," Dmitry Peskov said.
Paul Whelan had hand-written a sign for this final court hearing, pressing it to the glass of his cage in court to denounce his trial as a sham. TV cameras were banned from filming on Monday, supposedly as a coronavirus precaution.
So Whelan raised his voice to shout his innocence to the photographers instead. With two FSB [Russia's Federal Security Service] guards at his side in black balaclavas, he denounced the charges against him as fabricated and "ridiculous".
"They have got this so wrong, and all for political purposes," he told the BBC. At past hearings, he has been openly angry and frustrated - talking over the judge and accusing his interrogators of threats and coercion. On Monday, he was calm, even smiling - waving to the three ambassadors who came to court to support him, all in facemasks and gloves and carefully spaced out on the wooden benches like the press.
Paul Whelan had already declared this verdict "pre-ordained", but when it came, no-one bothered to translate it. The American was left shrugging, appealing to the judges to tell him his fate "po angliisky" - in English. The panel of three ignored him, and swept out of court in their gowns.
Who is Paul Whelan?
Paul Whelan is a citizen of four countries - the US, Canada, the UK and the Irish Republic.
From Novi, Michigan, he was born in Canada to British parents and moved to the US as a child.
Military records show he joined the US Marine Reserves in 1994, about six years after he had reportedly begun work as a police officer in Michigan.
He served two tours in Iraq, in 2004 and then 2006, before becoming a security executive. It was while serving in the marines that he made his first trip to Russia, and went on to visit the country many times.
Paul Whelan was arrested in his hotel room in central Moscow in December 2018.
He says he was getting ready for a wedding when an old friend turned up unexpectedly and gave him a flash drive containing what Whelan's lawyer says his client thought were holiday photographs.
Moments later, security officers burst in and arrested him for receiving state secrets.
After Monday's verdict, his family said in a statement it was the Russian legal system which had been "found guilty of injustice".
"The court's decision merely completes the final piece of this broken judicial process. We had hoped that the court might show some independence but, in the end, Russian judges are political, not legal, entities," the statement said.