The Venezuelan National Assembly adopted on Tuesday a statement declaring country's President Nicolas Maduro an usurper with all the decisions made by the president and the executive bodies void, local media reported.

"The historic document, in which the parliament assumes the powers based on the constitution's articles 233, 333 and 250, has been adopted", the president of the country’s National Assembly, Juan Guaido, wrote on his Twitter page.

Nicolas Maduro, in turn, has promised to hold the opposition-run National Assembly accountable for "making fun" of the constitution.

“Those who want to make fun of the constitution, let them ridicule it, there will be justice […] The Supreme Court will put things in their place", Maduro was quoted as saying by the national AVN news agency.

The opposition-controlled National Assembly has also reportedly stepped up its standoff with Nicolas Maduro on Tuesday by offering an amnesty to anyone from the military who joins it in disavowing the Venezuelan leader. The "amnesty law" would extend also to civilian government officials who collaborate "in the restitution of constitutional order," Venezuelan parliament said.

"We are talking to middle and low-ranking military: break away from the fear," Juan Guaido was quoted as saying by AFP.

On 10 January, Maduro took the oath of office to begin his second presidential term, which will last until 2025. The Organization of American States, members of the Lima Group — except Mexico — and the United States refused to recognize Maduro's new term. On Friday, the Washington-based Venezuelan Supreme Court in Exile called on Guaido to take over the presidency. Guaido himself has declared his readiness to do so, adding that the country's constitution allowed him to call a new election.

Meanwhile, US Vice President Mike Pence has conducted a phone call with Venezuelan opposition leader to express the United States’ support, the White House said in a statement on Tuesday.

In turn, Juan Guaido has announced mass protests on 23 January, the anniversary of the removal from power of Marcos Perez Jimenez, the late Venezuelan president who was deposed as a result of the 1958 coup.