Marking the program's 20th anniversary, Obama on Monday cited the "extraordinary progress" that's been made in securing nuclear materials, and thanked Nunn and Lugar for their leadership.
Under the program, the U.S. has provided billions of dollars in equipment and know-how to help Russia and its ex-Soviet neighbors deal with Soviet the nuclear legacy. The program has helped deactivate more than 7,600 nuclear warheads.
The program is set to expire this spring. Russia has said it wants a major overhaul before it's extended.
(Copyright 2012 by The Associated Press. All Rights Reserved.)