A senior U.S. arms official is in Moscow to continue discussions on new arms agreements with Russia. The two sides will work on the run-up to the U.S.-Russian presidential summit meeting to be held next month.
U.S. Undersecretary of State John Bolton has arrived in Moscow where he's due to hold talks with Russian Deputy Foreign Minister Georgy Mamedov and other officials.
The talks are part of an ongoing effort to finalize an agreement to substantially reduce the number of strategic nuclear warheads held by the two countries.
Both President Bush and Russian President Vladimir Putin say they want to cut nuclear stockpiles to between 1,700 and 2,200 warheads over the next 10 years.
This would represent a reduction of more than one third from current arsenals held by the two former cold war enemies.
Teams of negotiators for both sides report progress on a major new agreement.
However differences remain over final details, such as how to count missiles which carry more than one warhead, and whether the missiles are destroyed or merely placed in storage.
Officials say they hope these points can be worked out before President Bush travels to Russia to meet with President Putin late next month.
Relations between the U.S. and Russia have improved since President Putin strongly backed the U.S.-led war on terrorism.
Russian Foreign Minister Igor Ivanov met with U.S. Secretary of State Colin Powell in Spain last week to review progress on the talks.
After that meeting, Mr. Ivanov said progress had been made on some of the remaining points.
The two presidents initially pledged to make new cuts during their summit meeting in the U.S. late last year, despite disagreement over related issues.
Russia objected when President Bush decided to back out of the 1972 anti-ballistic missile treaty, in order for the U.S. to push ahead with a new anti-missile shield.