The White House announced early Saturday morning that Iran would release Xiyue Wang, an American held in that country since 2016, as part of a prisoner exchange.

“After more than three years of being held prisoner in Iran, Xiyue Wang is returning to the United States,” President TrumpDonald John TrumpTrump says he will ‘temporarily hold off’ on declaring Mexican drug cartels as terror organization House Judiciary Committee formally receives impeachment reportArtist behind gold toilet offered to Trump sells banana duct-taped to a wall for 0,000MORE said in a statement.

The U.S. has pushed for the release of Wang, a Princeton University graduate student who was charged with espionage and in 2017 sentenced to 10 years in prison. Americans officials denied that he was a spy.

Wang flew on a Swiss government airplane from Tehran to Zurich and was met there by the State Department’s special envoy for Iran, Brian Hook, according to The New York Times.

The U.S. released Iranian scientist Masoud Soleimani in exchange for Wang. Soleimani was arrested last fall on charges of violating trade sanctions against Iran and was expected to be released from prison under a plea agreement.

“Glad that Professor Massoud Soleimani and Mr. Xiyue Wang will be joining their families shortly. Many thanks to all engaged, particularly the Swiss government,” Iranian Foreign Minister Mohammad Javad Zarif tweeted early Saturday.

Glad that Professor Massoud Soleimani and Mr. Xiyue Wang will be joining their families shortly. Many thanks to all engaged, particularly the Swiss government. pic.twitter.com/1TeZUL0CDG

Javad Zarif (@JZarif) December 7, 2019

“We thank our Swiss partners for their assistance in negotiating Mr. Wangs release with Iran,” Trump said in his statement Saturday.

“The highest priority of the United States is the safety and well-being of its citizens. Freeing Americans held captive is of vital importance to my Administration, and we will continue to work hard to bring home all our citizens wrongfully held captive overseas.”