The US and Russia have exchanged jailed US basketball star Brittney Griner for notorious arms dealer Viktor Bout, held in an American prison for 12 years.

President Joe Biden said Griner was safe and on a plane home from the United Arab Emirates.

“I’m glad to say Brittney’s in good spirits… she needs time and space to recover,” he said at the White House.

Griner was arrested at a Moscow airport in February for possessing cannabis oil and last month sent to a penal colony.

The Biden administration proposed a prisoner exchange last July, aware Moscow had long sought Bout’s release.

The elaborate swap involved two private planes bringing the pair to Abu Dhabi airport from Moscow and Washington respectively, and then flying them home. According to Politico website they walked past each other on the airport tarmac.

“The Russian citizen has been returned to his homeland,” the Russian foreign ministry said in a statement, although he was not yet thought to have arrived on Russian soil.

Russian news agencies said he was still being flown to Vnukovo airport near Moscow.

Speaking in the Oval Office, Griner’s wife Cherelle praised the efforts of the Biden administration in securing her release: “I’m just standing here overwhelmed with emotions.” The ordeal had been one of the darkest moments of her life, she added.