MOSCOW (AP) — American basketball star Brittney Griner appeared in a Moscow-area court for trial Friday, about 4 1/2 months after she was arrested on cannabis possession charges at an airport while traveling to play for a Russian team.

Griner was arrested in February at Moscow’s Sheremetyevo Airport. Police said she was carrying vape canisters with cannabis oil. The Phoenix Mercury center and two-time U.S. Olympic gold medalist could face up to 10 years in prison if convicted of large-scale transportation of drugs.

Fewer than 1% of defendants in Russian criminal cases are acquitted, and unlike in the U.S., acquittals can be overturned.

At a closed-door preliminary hearing Monday in the Moscow suburb of Khimki, Griner’s detention was extended for another six months, to Dec. 20.

The athlete’s detention and trial come at an extraordinarily low point in Moscow-Washington relations. Griner was arrested less than a week before Russia sent troops into Ukraine, which aggravated already high tensions between the two countries.

The invasion led to sweeping sanctions imposed by the United States, and Russia denounced the U.S. for sending weapons to Ukraine.

Kremlin spokesman Dmitry Peskov on Friday denied politics played a role in Griner's detention and prosecution. .

“The facts are that the famous athlete was detained in possession of prohibited medication containing narcotic substances,” Peskov told reporters. “In view of what I've said, it can’t be politically motivated," he added.

Griner’s supporters have kept a low profile in hopes of a quiet resolution, until May, when the State Department reclassified her as wrongfully detained and shifted oversight of her case to its special presidential envoy for hostage affairs — effectively the U.S. government’s chief negotiator.

Griner’s wife, Cherelle, has urged President Joe Biden to secure her release, calling her “a political pawn.”

“It was good to see her in some of those images, but it’s tough. Every time’s a reminder that their teammate, their friend, is wrongfully imprisoned in another country,” Phoenix Mercury coach Vanessa Nygaard said Monday.

The coach hoped that Biden would "take the steps to ensure she comes home.”

Griner’s supporters have encouraged a prisoner swap like the one in April that brought home Marine veteran Trevor Reed in exchange for a Russian pilot convicted of drug trafficking conspiracy.

Russian news media have repeatedly raised speculation that she could be swapped for Russian arms trader Viktor Bout, nicknamed “the Merchant of Death,” who is serving a 25-year sentence on conviction of conspiracy to kill U.S. citizens and providing aid to a terrorist organization.

Russia has agitated for Bout’s release for years. But the wide discrepancy between Griner’s case — which involves alleged possession of vape cartridges containing cannabis oil — and Bout’s global dealings in deadly weapons could make such a swap unpalatable to the U.S.

Others have suggested that she could be traded in tandem with Paul Whelan, a former Marine and security director serving a 16-year sentence on an espionage conviction that the United States has repeatedly described as a setup.

U.S. Secretary of State Antony Blinken, when asked Sunday on CNN whether a joint swap of Griner and Whelan for Bout was being considered, sidestepped the question.

“As a general proposition ... I have got no higher priority than making sure that Americans who are being illegally detained in one way or another around the world come home,” he said. But he said he could not comment “in any detail on what we’re doing, except to say this is an absolute priority.”