The sanctions target Venezuelan governors who back Maduro and have prevented humanitarian aid from entering the country.
"The illegitimate Maduro regime's attempts to blockade international aid intended for the Venezuelan people are shameful," Treasury Secretary Steven Mnuchin said. "Treasury is targeting four state governors aligned with former President Maduro for standing in the way of severely needed humanitarian assistance and prolonging the suffering of the Venezuelan people."
Sanctions have already been placed on Maduro's intelligence services and the state-owned oil company Petroleos de Venezuela.
Pence arrived in Bogota, Colombia, earlier Monday to meet with Venezuelan opposition leader Juan Guaido, the nation's U.S.-recognized interim president, and talk to leaders in the region about the ongoing crisis. He called Maduro an "usurper" and blasted supporters for blocking highways and bridges to disrupt aid, calling it "unconscionable." Pence said Maduro's troops opened fire on civilians and forcing Venezuelans to starve.
"He literally danced while truckloads of food and medicine burned," Pence said as he addressed the Lima Group.
He directed his message to the people of Venezuela, saying the Trump administration is behind them 100 percent. About 200 troops have already defected from Maduro's regime.
"Socialism is dying and liberty and prosperity are being reborn before our eyes," Pence said. "Despite the brutality that the world witnessed this weekend, a new day is coming to Latin America."
Guaido declared himself interim president last month and has the full backing of the United States and some allies. Guaido supporters say Maduro won an illegitimate election and Guaido, as head of the National Assembly, should be the country's leader. Russia and Iran have thrown their support behind Maduro.
A senior Trump administration official said the United States will bring the "full measure of economic and diplomatic weight" to bear on Venezuela.
Guaido could call for a use of force against Maduro to break through the blockade. His government representative confirmed the plan in a tweet late Sunday.
U.N. High Commissioner for Human Rights Office Michelle Bachelet said violence should be "avoided at any cost and for lethal force not to be used in any circumstances."
Pence also said Colombia his strongest ally in the region and warned Maduro not to "test the commitment to our ally or the resolve of the United States of America."