Jailed Venezuelan opposition leader Leopoldo Lopez is refusing to appear in court in an attempt to pressure the government to respond to a United Nations request for his freedom.

Lopez has been jailed since February for his role in the street demonstrations that shook the socialist Latin American country this winter and spring. He is charged with inciting violence.

He was scheduled to appear in court Tuesday, but refused to leave the military prison where he is being held, citing the court's refusal to respond to U.N. demands for his freedom.

The U.N. Working Group on Arbitrary Detentions has called on Venezuela to immediately release Lopez and other jailed government opponents. Last week, the U.N.'s top human rights official repeated the demand.