In a statement, U.S. treasury secretary Steven Mnuchin said:"We are sanctioning members of Maduro's security forces in response to the reprehensible violence, tragic deaths, and unconscionable torching of food and medicine destined for sick and starving Venezuelans".
The six include Major General Richard Jesus Lopez Vargas, the commander of the Venezuelan National Guard.
Guaido was recognized as interim president by the Lima Group countries (except for Mexico), as well as by Albania, Georgia, the United States, and the Organization of American States.
His reappearance in Venezuela would pose an immediate challenge to the embattled Maduro, who will have to decide whether to arrest him for defying a travel ban - thereby provoking strong global condemnation - or allow him to enter unmolested, which would undermine his authority, analyst say.
In this photo provided by Ecuador's Presidential Office, Ecuador's President Lenin Moreno, center right, and his wife Rocio Gonzalez, right, welcome Venezuela's self-declared interim president Juan Guaido, center left, and his wife Fabiana Rosales during a meeting in Salinas, Ecuador. Guaido said he was "taking off", but did not say where the plane was heading.
The United States and about 50 other countries recognise Guaido as Venezuela's president, arguing that Maduro's re-election a year ago was a sham. "We will continue expanding cooperation and strengthening our relations", he said. "This has acquired special significance now that Venezuela is facing a frontal attack and unabashed interference in its domestic affairs", he said.
Maduro was supported by Russia, Bolivia, Iran, Cuba, Nicaragua, El Salvador and Turkey.
French Ambassador Francois Delattre told reporters: "The American draft does not represent a legal basis for a use of force, nor an attempt to undermine the sovereignty of Venezuela".
At a joint press conference following their talks, Rodriguez said Venezuela will continue to strengthen relations with Russian Federation and expand bilateral cooperation.
The socialist president warned last week that Guaido should "respect the law" and would have to "face justice" if he returns to the country.
USA officials have taken action against six current or former Venezuelan security chiefs accused of controlling the groups which have blocked emergency supplies, including much-needed food and medicine, from reaching people in the strife-torn Latin American country. This allows people from countries affected by armed conflict or natural disaster to live and work in the United States for a limited amount of time. Vice-President Mike Pence led talks on trying to get Nicolas Maduro out of power, and hit other Venezuelan politicians who support Maduro with sanctions too. I think that if he were arrested on his return, you would see a very large reaction on the part of the Venezuelan people and on the part of the worldwide community.