U.S. Vice President Mike Pence speaks after a meeting with President Donald Trump and Congressional Democrats about the U.S. government partial shutdown and the president's demand for a border wall in the Situation Room at the White House in Washington, U.S., January 9, 2019. REUTERS/Joshua Roberts/File Photo

WASHINGTON (Reuters) - U.S. Vice President Mike Pence said he had spoken by phone on Tuesday with Venezuelan opposition leader Juan Guaido, a show of support for him and a further sign of U.S. displeasure with Venezuelan President Nicolas Maduro.

Pence’s intent in the call to Guaido, who is head of the opposition-run National Assembly, was to express U.S. support for the assembly as the “only legitimate democratic body in the country,” a White House official said.

Earlier on Tuesday, Venezuela’s Congress formally declared Maduro a “usurper” after last year’s disputed elections, and CNN reported that U.S. President Donald Trump was considering recognizing Guaido as Venezuela’s legitimate president.

The Trump administration has also been weighing whether to levy a new round of economic sanctions against Venezuela to pressure Maduro, who was inaugurated on Jan. 10. He has faced heavy criticism that his leadership is illegitimate following a 2018 election widely viewed as fraudulent.

Last week, Guaido said he was willing to replace Maduro if he had the support of the military. Several government officials have said he should be arrested for treason and on Sunday he was briefly detained by intelligence agents.

In his call to Guaido, Pence lauded “his courageous leadership following his arrest and intimidation” at the weekend, the White House official said.

“The vice president firmly emphasized that the long-standing goal of the United States and all freedom-loving nations is to restore democracy to Venezuela through free and fair elections, and end the unprecedented humanitarian and economic crises in the once-rich cradle of Bolivar,” the official said.

“Vice President Pence encouraged Mr. Guaido to build unity among political groups, and pledged continued support from the United States until democracy is restored,” the official said.