Evan Gershkovich (Photo: Independent)

US consular officials have not had access to the reporter since his detention on March 29, in breach of a consular convention Moscow signed with Washington.

Russia's embassy in Washington has not responded to Blinken's remarks.

Russia's FSB security service said on March 30 that it had arrested Gershkovich, accusing him of gathering information about a Russian defense company that was a state confidentiality.