MOSCOW — Imposing more sanctions on Iran over its nuclear program is not the best option, but it cannot be excluded, Russian President Dmitry Medvedev said Saturday.Russia is a key player in mediations on Iran's nuclear program, which the United States and other Western nations believe is geared toward producing atomic weapons. Iran insists its nuclear technology has a solely peaceful purpose, but the West is frustrated by Iran's perceived reluctance to prove that.Medvedev said in a statement to members of the League of Arab States in Moscow that "we are convinced that the sanctions path is not optimal.""At the same time, developments along this scenario can't be excluded," the statement said.Mixed signals on the controversial issue continue to emanate fromMoscow, with some officials highlighting the importance of a diplomaticsolution to the stalemate while others suggest sanctions may now be theonly way to prevent Iran joining the nuclear club.Russia is a longtime trade partner of Iran, giving it more leverage than Western nations — and perhaps more patience.But Russian Foreign Minister Sergey Lavrov said last week that Iran wasallowing an opportunity for mutually beneficial dialogue with the Westto "slip away."Russia and the United States — the world's premier nuclear superpowers— on Friday struck a landmark agreement cutting their nuclear arsenalsby a third. Both view a nuclear-armed Iran — whose leaders have saidIsrael should be wiped off the map — as a destabilizing factor in theMiddle East and the wider world. Washington and Moscow have both haileddiplomacy over sanctions as the favored solution.