WASHINGTON — Hailing two decades of efforts to help the former Soviet Union secure nuclear weapons stockpiles, President Obama said Monday the world must continue to stand guard against nuclear threats, including terrorists who seek to gain control of such weapons.
‘‘We cannot let our guard down,’’ Obama said, calling efforts to combat nuclear terrorism one of his top priorities as president.
Obama praised the 20-year-old Cooperative Threat Reduction program, which has provided billions of dollars in US equipment and know-how to help Russia and former Soviet bloc nations safeguard and dismantle nuclear and chemical weapons.
The program, initiated by Senator Richard Lugar, an Indiana Republican, and former senator Sam Nunn, a Georgia Democrat, has helped deactivate more than 7,600 nuclear warheads.
Marking the program’s 20th anniversary, Obama cited the ‘‘extraordinary progress’’ that has been made in securing nuclear materials and thanked Nunn and Lugar for their leadership. In a speech in Washington, the president called Nunn and Lugar ‘‘visionaries’’ who ‘‘challenged us to think anew’’ about ways to secure nuclear stockpiles produced during the Cold War. He also said they were models for bipartisan cooperation, who showed great integrity, decency, and leadership over their long careers.
Obama called Lugar, who was defeated in a bid for reelection, a friend, and said his legacy — and Nunn’s — is ‘‘a safer and more secure world.’’
The program Nunn and Lugar created provided reinforced rail cars to carry nuclear warheads, high-tech security systems for storage sites, and funds for the dismantling of mothballed nuclear submarines and other weapons. It played a major role in preventing deadly weapons from falling into the wrong hands while the Russian government was facing a severe money crunch amid an economic meltdown and political turmoil that followed the 1991 collapse of the Soviet Union.
The program is set to expire this spring, and Russia has said it will not automatically extend it without a major overhaul.
Obama noted statements about the program’s future by Russian leaders and said the US response is, ‘‘Let’s update it. Let’s work with Russia as an equal partner. Let’s continue the work that is so important.’’
Obama said he was optimistic that a new agreement can be reached.
Defense Secretary Leon Panetta spoke before Obama and also heaped praise on his former congressional colleagues. Panetta awarded Nunn and Lugar the Defense Department’s Medal for Distinguished Public Service, the Pentagon’s highest civilian honor.
‘‘We can say that the course of history changed for the better because these two men helped the nation confront the threat of nuclear proliferation at the end of the Cold War,’’ Panetta said. ‘‘The world would have been, without question, a far more dangerous and threatening place were it not for these two patriots.’’