On January 23 Venezuelan National Assembly Speaker Juan Guaido proclaimed himself as the country's acting president.
Secretary of State Mike Pompeo has said that China's financing of President Nicolas Maduro's government is prolonging the crisis in Venezuela.
The civilian militia, created in 2008 by the late former president and Maduro mentor Hugo Chavez, reports directly to the presidency and is meant to complement the armed forces.
Maduro, who calls Guaido a US puppet, said he aimed to raise the number of militia members to three million by year-end from what he said was more than 2 million now.
In his speech at the ceremony, Maduro stated that they aim to increase the number of militia to 3 million and that the militias have an important place in maintaining peace in the country. Hyperinflation, shortages of food and medicine and other hardships have forced more than three million Venezuelans - about one-tenth of the population - to flee the country in the last few years. "Maduro relies on the support he receives from the Cuban military and intelligence services to retain his hold on power because he does not have the support of the Venezuelan people", he added. In Zulia state, the site of the OPEC member's first oil well and home to Venezuela's second-largest city, Maracaibo, he said: "We are here to check on the situation, your suffering".
Separately on Saturday, two employees of Venezuela's central bank who were arrested after meeting with Guaido earlier this week were freed, rights group Penal Forum said.
Since the start of the year, the U.S. has stepped up sanctions against Venezuela, hitting the oil sector in particular, along with the gold exports sector, as it seeks to dry up capital flows available to the government.