"Today marks two years since US citizen and Marine veteran Matthew Heath was wrongfully detained in Venezuela," State Department spokesman Ned Price said in a statement.

Heath was labeled a spy by authorities in Caracas who accused him of trying to attack oil and power facilities. Price descried the charges as "specious."

"We continue to press the (President Nicolas) Maduro regime for the immediate and unconditional release of Matthew and all other wrongfully detained US nationals in Venezuela," the statement continued.

According to the United States, 11 American citizens are being held in the country.

Two Americans were released in March, just after a high-level White House delegation visited Caracas.

Venezuela and the United States broke off relations in early 2019, as Washington did not recognize Maduro's re-election.