The United States warned on Friday that it had received new reports from within Democratic Republic of Congo accusing Congolese troops of actively carrying out a campaign of killing and raping women and children in the central Kasai region.
U.S. Ambassador to the United Nations, Nikki Haley, called for action.
"Reports of the Congolese government's campaign of murder and rape of women and children should shock us into action.
These allegations must be investigated and those responsible held accountable," Haley said in a statement.
The Democratic Republic of Congo mission to the United Nations was not immediately available for comment.
The top U.N. human rights official last week called for an international investigation into massacres and other crimes committed in the Kasai region where at least 42 mass graves have been found.
"It is past time for the Human Rights Council to take decisive action and launch an independent investigation into the human rights violations and abuses in the DRC.
This is the core mission of the (council)," Haley said.
Hundreds have been killed and 1.3 million displaced in central Congo since last August in fighting between a militia and government forces.
Two U.N. sanctions monitors disappeared there in March and their bodies were found two weeks later.
Violence has risen nationally since President Joseph Kabila stayed in power after his mandate ended in December 2016.