American missionary Josh Holt, held by Venezuela without trial on weapons charges since 2016, was heading home with his wife on Saturday after the South American country's socialist government unexpectedly released him.

The freeing of the Mormon missionary from Utah came despite deepening U.S.-Venezuelan tensions that in the last week saw tit-for-tat expulsions of diplomats, Washington's refusal to recognize the May 20 re-election of Venezuelan President Nicolas Maduro, and the imposition of new U.S. sanctions on Caracas.

Speaking at a news conference in Caracas, Communications Minister Jorge Rodriguez said Holt and his wife, Thamy, were freed as part of efforts by Maduro's government to maintain "respectful diplomatic relations" with Washington.

"This type of gesture ... allows us to consolidate what has always been our standpoint: dialogue, agreement, respect for our independence, respect for our sovereignty," Rodriguez said.

Holt and his wife had been charged with espionage, violence and spreading activities against Venezuela's constitutional order, he said.

They were expected to arrive in Washington on Saturday evening and join Holt's family at the White House, U.S. President Donald Trump said on Twitter.

Utah Senator Orrin Hatch said in a statement that Holt's release followed two years of intense lobbying, working with two presidential administrations, countless diplomatic contacts around the world, and Maduro himself.

"I could not be more honored to be able to reunite Josh with his sweet, long-suffering family," Hatch said.

In a statement on Facebook, Holt's family gave thanks "to all who participated in this miracle," but asked to be allowed to meet him and his wife before giving any further statements or interviews.

The details of what led to Holt's release were not immediately clear. It followed by a day a meeting in Caracas between Maduro and U.S. Senator Bob Corker, the chairman of the U.S. Senate Foreign Relations Committee.

Venezuelan authorities arrested Holt in June 2016 while he was in Venezuela for his wedding, and he has been held without trial at the Helicoide, the headquarters of the intelligence agency Sebin, where inmates revolted earlier this month.

His family says he was framed on the weapons charges and the United States accused Caracas of using him as a bargaining chip in sanctions talks.

The United States accuses Maduro's government of stifling democracy, repressing the opposition and massive corruption. Maduro says Washington is conspiring to topple him and seize the OPEC member's large oil reserves.

He blames a U.S. "economic war" for Venezuela's fiscal woes, including hyper-inflation and food and medicine shortages that have triggered mass emigration.

Eva Golinger, a New York-based immigration lawyer once dubbed the "sweetheart" of Venezuela's socialist revolution by former Venezuelan President Hugo Chavez, said on Twitter that Maduro freed Holt as a gesture to gain legitimacy and win the lifting of U.S. sanctions.

"Surely Venezuela gets something in return," wrote Golinger, who has become a Maduro critic. "Stay tuned."