An opposition demonstrator uses a home made gas mask while clashing with riot police during the so called "mother of all marches" against Venezuela's President Nicolas Maduro in Caracas, Venezuela, April 19, 2017. REUTERS/Carlos Garcia Rawlins

WASHINGTON (Reuters) - The United States is closely watching the political situation in Venezuela and is worried the government of President Nicolas Maduro is working to silence the opposition, U.S. Secretary of State Rex Tillerson said on Wednesday.

“We are concerned that the government of Maduro is violating its own constitution and is not allowing the opposition to ... organize in a way that expresses the views of the Venezuelan people,” Tillerson told a news conference. “We are concerned about that situation. We’re watching it closely and working with others ... to communicate those concerns.”