The two Americans are imprisoned in Russia and attempts to free the pair have proven difficult due to the deterioration of relations between the two countries following the invasion of Ukraine.

According to the White House, Biden first met with Elizabeth Whelan, Paul's sister, before talking with Cherelle Griner, the wife of Brittney Griner, and the athlete's agent Lindsay Colas.

White House press secretary Karine Jean-Pierre said in a statement after the meetings that the US President repeated his "continued commitment to working through all available avenues to bring Brittney and Paul home safely" to the families.

"He asked after the well-being of Elizabeth [Whelan] and Cherelle [Griner] and their respective families during this painful time," Jean-Pierre said

"The President appreciated the opportunity to learn more about Brittney and Paul from those who love them most, and acknowledged that every minute they are being held is a minute too long."

Officials from the White House stressed that the meetings do not signal a breakthrough in negotiations for their release between the US and Russia.

However, Cherelle Griner expressed her gratitude to the US Government's dedication to releasing her partner.

"I want to thank President Biden for today's meeting," she said in a statement.

"It was an honor (sic) to speak with him directly about the Brittney we know and love, and to thank him for the Administration's efforts to secure her release.

"I've felt every minute of the grueling (sic) seven months without her.

"I look forward to the day my wife is back home.

"As my family and I continue on this journey, I'd like to thank the broad coalition of friends, leaders and supporters who continue to stand with us and advocate for Brittney’s swift and safe return.

"Let's share a unified commitment to bringing all Americans home to their families and loved ones."

Paul Whelan's brother, David, admitted that "it means a lot" to his family that Biden displayed his "continued commitment" to freeing his sibling and Griner.

John Kirby, a spokesman for the National Security Council, suggested that Russia has not responded to the US' "serious offer" to secure the release of Griner and Whelan.

It has been speculated that Russian arms dealer Viktor Bout has been at the centre of the US attempts.

Griner was sentenced to nine years in a Russian prison last month on drug possession charges after she entered the country with vape cannisters containing cannabis oil in February.

She is currently appealing her nine-year sentence.

Whelan was sentenced to 16 years in prison in 2020 on espionage charges.

Both prisoners have been classified as wrongfully detained by the US State Department.