Trevor Reed, a 30-year-old from Texas who was jailed in Russia in 2020, was exchanged for Konstantin Yaroshenko, 53, who had been serving a 20-year US prison sentence since 2011.

Russian foreign ministry spokeswoman Maria Zakharova said the two had been exchanged on Wednesday "as a result of a lengthy negotiations process".

Russian state television showed Reed -- dressed all in black and carrying a large bag -- escorted onto a plane at Moscow's Vnukovo airport by men in military uniform.

His father Joey Reed told CNN that Trevor was moved to a Moscow prison this week and then flown to Turkey where the swap took place.

"The American plane pulled up next to the Russian plane and they walked both prisoners across at the same time, like you see in the movies," he said.

US President Joe Biden said the swap required "difficult decisions".

"The negotiations that allowed us to bring Trevor home required difficult decisions that I do not take lightly," Biden said in a statement.

"His safe return is a testament to the priority my administration places on bringing home Americans held hostage and wrongfully detained abroad," he added.

Secretary of State Antony Blinken also praised the swap.

"I am pleased to announce the release of US citizen Trevor Reed, who was wrongfully detained in Russia," Blinken said in a statement.

"We also remain committed to securing the freedom of all US nationals wrongfully detained abroad," he added.

Reed was sentenced in July 2020 to nine years in prison by a Russian court after allegedly attacking police officers while drunk.

While being driven to a police station, he allegedly grabbed the arm of a police officer, causing the car they were in to swerve, and elbowed another officer in the abdomen.

- Hunger strike -

Reed pleaded not guilty to the charges, saying he remembers nothing of the incident.

While imprisoned in a penal colony in Russia's Mordovia Republic, some 500 kilometres (300 miles) southeast of Moscow, Reed staged a hunger strike over what he said was the violation of his rights.

His lawyer Sergei Nikitenkov said at the time that Reed was several times put in an isolation cell and prison staff were withholding letters from him.

Nikitenkov told the Interfax news agency Wednesday that his client did not ask for a pardon.

"He agrees with the fact of the exchange, approves it, but at the same time Trevor does not admit his guilt," he said.

Russian television reported that Yaroshenko had already arrived back in the country.

He was arrested in Liberia in 2010 for drug trafficking, then transferred to the United States, where he was sentenced to 20 years in prison in September 2011.

Yaroshenko's lawyer Alexei Tarasov told the RIA Novosti state news agency: "I would call this an Easter miracle," referring to Orthodox Easter.

He said that the swap was carried out in a third country and "had been in the works for a very long while".

The Russian's health "leaves much to be desired," Tarasov told state news agency TASS.

In June 2021, Yaroshenko's family sent a letter to Biden requesting a pardon for the jailed pilot.

Yaroshenko's wife Viktoria told RIA Novosti that her husband was exchanged in Turkey, and she was waiting for him at a Moscow airport.

An exchange of prisoners was on the agenda last June during a summit meeting between Biden and Russian President Vladimir Putin in Geneva.

At the time, Putin hinted that Reed's case could be resolved quickly, calling him a "drunk and a troublemaker".

Another US citizen, Paul Whelan, a former security official at an auto parts company, remains in a Russian prison serving 16 years on espionage charges.

Biden referred to his case in a statement, saying: "We won't stop until Paul Whelan and others join Trevor in the loving arms of family and friends."