G8 summit could START Russia-U.S. missile reduction
Signed between the USSR and the U.S. in 1991, the START treaty came into force in 1994. It obliged each side to limit the number of nuclear warheads, submarine missiles and bombers.
The deal is now due to be renewed. Russia and the U.S. are having talks about a new agreement, but a mutually acceptable form has yet to be found.
Russia says the terms being offered by the United States won't allow any real control over strategic arms.
In May, the U.S. ambassador to Russia, William Burns, said Washington will do all it can to ensure that a new treaty is signed this year.
Dmitry Medvedev and George Bush are hoping to discuss security issues between the two countries, including the START treaty, on the sidelines of the upcoming G8 summit in Japan.