Over 40 organisations - including the National Association for the Advancement of Coloured People (NAACP), Human Rights Campaign, the Women's National Basketball Players Association (WNBPA) and GLAAD - have joined with the player's wife Cherelle Griner in signing the letter to the head of state and his vice-president Kamala Harris.

"President Biden and Vice President Harris, we urge you to make a deal to bring our team-mate, wife, sister, hero, and friend Brittney Griner home swiftly and safely," read the letter.

Griner was arrested on February 17 in Russia on drug charges at Sheremetyevo International Airport near Moscow for carrying vaporiser cartridges containing hashish oil, an illegal substance in Russia.

This came one week before the invasion of Ukraine by Russia, following weeks of uncertainty over whether a conflict would surface.

Her detention was extended until May in mid-March and was then pushed back to last Saturday (June 18), with the new date set to be her pre-court trial.

Since then, this was extended until at least July 2 at "the request of the investigation", according to Russian state news agency TASS.

The charge can carry a maximum penalty of 10 years in prison.

The American has represented the women's national basketball team since 2011 and is a two-time Olympic champion.

Griner has also played overseas in Russia since 2014 in the WNBA off-season, where she has played domestically for Phoenix Mercury since making her club debut in 2013.

In response to the letter, National Security Council spokesperson Adrienne Watson said the President was looking to assist anyone wrongfully detained.

"President Biden has been clear about the need to see all US nationals who are held hostage or wrongfully detained abroad released, including Brittney Griner," she said.

"The US Government continues to work aggressively - using every available means - to bring her home."

A senior administration official said the White House was in constant contact with the player, according to CNN.

"The President's team is in regular contact with Brittney's family and we will continue to work to support her family," they said.

"Secretary [Anthony] Blinken has spoken with Brittney's wife recently (including yesterday) and the White House is closely coordinating with the Special Presidential Envoy for Hostage Affairs, who has met with Brittney's family, her teammates, and her support network."

Griner was named as an honorary WNBA All-Star starter for this season in solidarity with her detainment.