The inauguration ceremony took place in the building of the country's Supreme Court as the opposition-controlled parliament, the National Assembly, has been excluded from participation in the political life of Venezuela.
Article 231 of the Venezuelan Constitution allows the ceremony to take place in the Supreme Court if the head of state cannot take the oath before the parliament.
Earlier in the day, a spokeswoman for EU foreign policy chief Federica Mogherini said that the European Union and its member states would not send representatives to the inauguration of Venezuelan President Nicolas Maduro.
On US-Venezuela Relations
At the inauguration day, US Secretary of State Mike Pompeo condemned Maduro's swearing in as president and called it an 'illegitimate usurpation of power.'
"The United States condemns Maduro's illegitimate usurpation of power today following the unfree and unfair elections he imposed on the Venezuelan people on May 20, 2018," Pompeo said in the release.
He went on stressing that the United States will continue to impose visa revocations and other restrictions for current and former Venezuelan officials responsible for the conflict in the country.
"We also have implemented and will continue to impose visa revocations and other restrictions for current and former Venezuelan government officials and their family members believed to be responsible for or complicit in human rights abuses, acts of public corruption, and the undermining of democratic governance," Pompeo said in the release.
This comes after on 6 January Pompeo has welcomed the decision of the Lima Group of Latin American countries plus Canada not to recognize the inauguration of Venezuela's incumbent President Nicolas Maduro following his re-election in May.