Freed missionary welcomed to White House

A Mormon missionary from Utah has been freed and returned to the US after being held for two years without trial in a Venezuelan jail.

Joshua Holt has visited the White House after being released from a prison in Venezuela. (AAP)

US President Donald Trump has welcomed to the White House an American held without trial for two years in a Venezuelan jail, saying he has undergone a "very tough ordeal".

Joshua Holt, 26, and his wife arrived on Saturday evening at Washington Dulles International Airport.

Venezuelan officials released the Holts after high-level talks between President Nicolas Maduro and US lawmakers.

Sitting with Trump and other US officials, Holt said he was "overwhelmed with gratitude" for those who worked for his release.

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

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