US President Joe Biden thanks Nigerian President Bola Tinubu on a phone call for releasing Binance exec Tigran Gambaryan

U.S. President Joe Biden expressed appreciation toward Nigeria President Bola Tinubu regarding the release of Binance executive Tigran Gambaryan last week.

Biden thanked Tinubu during a phone call, according to a statement released by The White House on Tuesday.

"President Biden offered his condolences on the recent flooding that has impacted northeastern Nigeria and underscored his appreciation for President Tinubu’s leadership in securing the release on humanitarian grounds of American citizen and former U.S. law enforcement official Tigran Gambaryan last week," according to The White House.

Gambaryan, a former agent for the U.S. Internal Revenue Service and Binance’s head of financial crime compliance, and another Binance executive, Nadeem Anjarwalla, were detained after arriving in Nigeria in February amid accusations of Binance making illegal transaction profits locally. Criminal charges were filed against them on Feb. 28. Anjarwalla later escaped from custody on March 22.

While being detained in a Nigerian prison, Gambaryan's family said he suffered from intense pain from a herniated disc and was unable to walk. He also had pneumonia and malaria. Charges were later dropped on Oct. 23.

During the call, Biden also acknowledged the country's work on the Bilateral Liaison Group on Illicit Finance and Cryptocurrencies, which launched on Oct. 23. As part of the group, the U.S. Department of Justice coordinates with Nigeria's government to "pursue cybercrime investigations and prosecutions."