The United States and Russia have agreed on a plan to accelerate installation of radiation detection devices at 350 Russian border crossings.
US officials said the development would mean the system would fully operational by 2011.
The programme aims to prevent nuclear smuggling from a country with the largest amount of nuclear material in the world.
"This announcement is a major cooperative step in counter-proliferation work in Russia," said Will Tobey, deputy administrator for the US's National Nuclear Security Administration.
Russia identified more than 480 cases of illicit trafficking of nuclear and radioactive material in 2006. While US officials said these cases were not believed to involve weapons-grade nuclear material, the number of cases underscores the scope of the problem.
Another US official said the detection system could have an important application in efforts to prevent North Korea, which last year tested its first nuclear device, from selling nuclear weapons or fuel.
"On the Russian border with North Korea we have detectors ... so we are able to monitor not only what is going into Russia, but also what might be coming out of North Korea," the official said.
Although US-Russian ties are increasingly tense over a number of major issues, Mr Tobey said efforts to combat the threat of nuclear proliferation "is a bright spot of cooperation" with Moscow.