President-elect Donald Trump says Venezuela's embattled opposition leader must be protected as President Nicolas Maduro takes the oath of office for a third six-year term.

Venezuela’s Nicolas Maduro has been sworn in for a third presidential term in what the country’s opposition movement has decried as “coup d’etat”, capping more than five months of dispute over last summer’s contested election.

The US announces an increased $25 million reward for information leading to the arrest of Venezuelas President Maduro on day he's sworn in for a third term.