WASHINGTON (Reuters) -U.S. Secretary of State Antony Blinken spoke by phone on Wednesday with American citizen Paul Whelan, who is being held in a Russian prison, according to a source familiar with the call.

Blinken told Whelan to "keep the faith and we’re doing everything we can to bring you home as soon as possible," CNN reported, citing a source.

Whelan, a former U.S. Marine, was arrested in 2018, held for 18 months in Lefortovo prison in Moscow and jailed for 16 years in 2020 on spying charges. He has denied the accusations.

The United States has designated Whelan as "wrongfully detained," a term that effectively says the charges are bogus and the case is politically driven.

U.S. ambassador to Russia, Lynne Tracy, visited Whelan in May in the prison in eastern Russia where he was being held.

(Reporting by Eric Beech, additional reporting by Humeyra Pamuk; Editing by Rami Ayyub, Alistair Bell and Deepa Babington)