U.S. President Barack Obama and Russian President Vladimir Putin will sign a new agreement on securing and destroying nuclear material to prevent the spread of nuclear weapons.
The two leaders made the announcement after talks on the sidelines of a G8 summit in Northern Ireland on June 17.
The new agreement will replace a 1992 deal that expired on June 17.
Obama hailed the agreement as a sign of the "kind of constructive, cooperative relationship" that moves the United States and Russia "out of a Cold War mindset."
Ben Rhodes, a spokesman for the National Security Council, said Russia had been reluctant to extend the agreement. Rhodes noted the previous deal had taken a "very aggressive and intrusive" approach to securing nuclear material in Russia.
The previous agreement was signed after the collapse of the Soviet Union and was known as the Nunn-Lugar agreement after former Democratic Senator Sam Nunn and former Republican Senator Richard Lugar.
On June 17, Nunn applauded the new deal, although he noted that some parts of the old one focused on chemical and biological weapons would not continue.
"We must find ways beyond this agreement to work together on these critical issues," he said. "I believe that we will."
Based on reporting by Reuters and ITAR-TASS