The United States is calling on the Iranian government to provide “credible answers” to what happened to a former FBI agent who was “abducted” while traveling in Iran in 2007.

“The United States will never forget Bob Levinson,” Secretary of State Antony Blinken said in a March 9 statement marking the 14th anniversary of his disappearance.

Blinken also called on Iran to “immediately and safely release” all U.S. nationals “unjustly held captive” in the country, saying: “The abhorrent act of unjust detentions for political gain must cease immediately.”

Levinson, who was born in March 1948, disappeared when he traveled to the Iranian Kish Island resort in March 2007. He was reportedly working for the CIA as a contractor at the time.

The United States has repeatedly called on Iran to help locate Levinson and bring him home, but Iranian officials said they have no information about his fate.

However, when he disappeared, an Iranian government-linked media outlet broadcast a story saying he was “in the hands of Iranian security forces.”

In December 2020, the previous U.S. administration imposed sanctions on two Iranian intelligence agents believed to be “involved in the abduction, detention, and probable death” of the former agent.