US basketball player Brittney Griner has begun serving her nine-year sentence for drug possession at a Russian penal colony, her lawyers and agent said.

Griner was transferred to a penal colony in Mordovia, about 350 kilometres (210 miles) east of Moscow, after a Russian court last month rejected her appeal of her sentence.

Her lawyers said they visited her earlier this week.

“Brittney is doing as well as could be expected and trying to stay strong as she adapts to a new environment,” her lawyers said in a statement.

The all-star centre with the WNBA’s Phoenix Mercury and two-time Olympic gold medallist was detained in February when customs agents said they found vape canisters containing cannabis oil in her luggage at Moscow’s Sheremetyevo Airport.

At her trial, Griner admitted to having the canisters in her luggage but said she packed them inadvertently in her haste to make her flight and had no criminal intent.

Her defence team presented written statements saying she had been prescribed cannabis to treat chronic pain.

The Biden administration has been trying for months to negotiate the release of Griner and another American jailed in Russia, Michigan corporate security executive Paul Whelan.

Whelan was also sent to a penal colony in Mordovia after being convicted of espionage-related charges in 2020 and sentenced to 16 years in prison.