The agreement resolves legal disputes that threatened to derail the programs, which send hundreds of millions of dollars a year to Russia for "cooperative threat reduction" efforts. It will be signed by week's end, according to Frederick Jones, a spokesman for President Bush's National Security Council.

"The agreement ensures that critical cooperation with Russia continues to combat the proliferation threat posed by large quantities of Soviet legacy weapons of mass destruction and missile(s)," Jones says.

The cooperation programs, initiated in 1992, comprise a broad range of initiatives meant to reduce the risk that old Soviet weapons of mass destruction will fall into the hands of rogue states or terrorists. Projects include constructing facilities to lock down nuclear material and warheads; strengthening security at labs storing dangerous biological pathogens; developing special facilities to destroy chemical weapons; and dismantling long-range missiles and bombers.

President Bush has hailed the programs as an important part of the administration's efforts to keep terrorists from obtaining weapons of mass destruction. But the programs' future has been in flux since 2004 due to a U.S.-Russian dispute over liability protections for U.S. companies, workers and government personnel working at Russian weapons sites.

The original agreement governing the projects gave U.S. workers blanket protection from liability for damages in case of an on-site accident. That might include, for example, the accidental release of nerve gas at a chemical weapons disposal facility. But Russia was reluctant to continue that arrangement based on concerns that it would indemnify U.S. workers even for intentional acts of sabotage.

The new pact essentially retains the same blanket protections for U.S. workers involved in projects already underway. For new projects, the countries will develop liability protections that are not as sweeping as the current agreement.

William Hoehn, a non-proliferation expert at the Russian American Nuclear Security Advisory Council, said the new agreement would ensure that old Soviet weapons stocks are properly secured and disposed of.