Some 450 0000 people are without shelter after 90 displacement camps were destroyed, Judith Suminwa Tuluka added.
The M23's advance is the gravest escalation in more than a decade of the long-running conflict in eastern DRC.
Rwanda rejects allegations from DRC, the United Nations (UN) and Western powers that it supports M23 with arms and troops.
The Prime Minister urged the world to act and to impose "dissuasive sanctions" amid mass displacements and summary executions.
"It is impossible to describe the screams and cries of millions of victims of this conflict", she added.
In the opening remarks at the 58th UN Human Rights Council in Geneva, UN Chief Antonio Guterres said that human rights around the world are being "suffocated" and referred to horrifying human rights abuses in the DRC.
--Reuters--