Washington (CNN) The number of detainees at Guantanamo Bay, Cuba has decreased for the first time since President Donald Trump came into office, the Pentagon confirmed Wednesday.

"The Department of Defense announced today the transfer of Ahmed Mohammed Ahmed Haza al Darbi from the detention facility at Guantanamo Bay to the government of the Kingdom of Saudi Arabia," the Pentagon said in a statement.

The Pentagon referred to al Darbi as an "al Qaeda terrorist." He pleaded guilty at a 2014 military commission to offenses relating to attempts to carry out terrorist attacks against shipping vessels in the Strait of Hormuz and off the coast of Yemen as well as an attack on a French oil tanker. He was approved for transfer in March.

Prior to that the most recent transfer of a detainee occurred on 19 January, 2017, shortly before Trump took office. Forty detainees remain in Guantanamo Bay.

"Al Darbi will serve out the balance of his 13-year sentence in Saudi Arabia. He has waived his right to appeal," the Pentagon said.

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