US rejects Maduro severing diplomatic ties

The US has rejected a decision by Venezuelan President Nicolas Maduro to cut diplomatic ties with Washington.

Venezuela opposition leader Juan Guaido (waving) has said he is willing to replace the president. (AAP)

The United States has rejected a move by Venezuela's Nicolas Maduro to break diplomatic ties, saying it does not think he has the authority to cut ties and it will conduct relations with a government led by opposition leader Juan Guaido.

"The United States maintains diplomatic relations with Venezuela and will conduct our relations with Venezuela through the government of interim President Guaido, who has invited our mission to remain in Venezuela," Secretary of State Mike Pompeo said in a statement on Wednesday.

"The United States does not recognise the Maduro regime as the government of Venezuela. Accordingly the United States does not consider former president Nicolas Maduro to have the legal authority to break diplomatic relations."

Guaido declared himself interim president on Wednesday, winning the backing of Washington and many Latin American nations and prompting Maduro, who has led the oil-rich nation since 2013, to break relations with the United States and to give US diplomats 72 hours to leave the country.

Pompeo, however, suggested that US diplomats planned to stay put and he demanded the Venezuelan military and security forces "continue protecting ... all Venezuelan citizens, as well as US and other foreign citizens in Venezuela.

"We call on all parties to refrain from measures that are inconsistent with the privileges and immunities enjoyed by members of the diplomatic community," he said.

"The United States will take appropriate actions to hold accountable anyone who endangers the safety and security of our mission and its personnel," he added.