Kony, she said, was an "evil mass-murderer" who used child soldiers to carry out atrocities in Uganda and other countries in central Africa.
"The sole purpose of the Lord's Resistance Army is to kill, maim and cause suffering," she said in a statement.
A video by advocacy group Invisible Children paints Kony as a brutal warlord. Kony was indicted by the International Criminal Court in 2005 on more than 30 counts of violations of international law, including war crimes, but remains at large.
Human Rights Watch last year said LRA fighting was escalating and this week, the U.N. High Commissioner for Refugees said attacks by the LRA has displaced an estimated 3,000 people.
"Kony will go down in history as one of the most brutal human rights abusers the world has ever seen," said Ros-Lehtinen. "We must never give up on our efforts to hold him accountable for his unspeakable actions."