Russia and the United States will sign a deal Tuesday on reducing stocks of weapons-grade plutonium, the Foreign Ministry said.
Under the agreement, each country is to dispose of 34 metric tons of weapons-grade plutonium removed from military programs by burning it in reactors, U.S. officials said.
The United States and Russia initially reached a similar deal on plutonium disposal in 2000, but it never went into force.
"Tomorrow in Washington a bilateral protocol will be signed to the agreement on the disposal of surplus weapons-grade plutonium," Deputy Foreign Minister Sergei Ryabkov said in an interview with Ekho Moskvy radio on Monday.
Presidents Dmitry Medvedev and Barack Obama are among four dozen leaders expected to take part in a nuclear security summit that began in Washington on Monday.
The two leaders last week signed the New START treaty committing them to reduce their atomic arsenals.