Story highlights The transfer brings the number of prisoners remaining at Guantanamo to 80

It also comes ahead of Obama's planned trip to Saudi Arabia next week

(CNN) The United States is transferring nine detainees from the detention facility at Guantanamo Bay to Saudi Arabia, the Pentagon said Saturday.

The transfer, which brings the number of prisoners remaining at Guantanamo to 80, comes amid President Barack Obama's renewed effort to close the prison -- one of the earliest pledges of his presidency.

It also comes ahead of Obama's planned trip to Saudi Arabia next week.

The Defense Department expressed gratitude to the kingdom in a statement on Saturday.

"The United States is grateful to the government of the Kingdom of Saudi Arabia for its humanitarian gesture and willingness to support ongoing U.S. efforts to close the Guantanamo Bay detention facility," the statement said.

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