NATO expressed regret Saturday over Russia's decision to suspend a key arms control treaty in Europe, describing it as "a step in the wrong direction." "The allies consider this treaty to be an important cornerstone of Euro stability and they would like to see it ratified as soon as possible," NATO spokesman James Appathurai said. Earlier Saturday, Moscow announced that President Vladimir Putin had signed a decree suspending Russia's participation in the CFE treaty due to "extraordinary circumstances ... which affect the security of the Russian Federation and require immediate measures." "NATO regrets this decision by the Russian Federation. It is a step in the wrong direction," Appathurai said. The CFE was signed in 1990 and extensively amended in 1999 in order to reflect changes created by the disintegration of the Soviet Union, and the fact that many former Warsaw Pact allies of the USSR had by then joined the North Atlantic Treaty Organization. It added the requirement that Moscow withdraw troops from the former Soviet republics of Moldova and Georgia. Russia ratified the amended version, but the United States and other NATO members have refused to do so. Russian troops have since left Georgia, although some of their equipment remains to be repatriated. But Moscow has refused to withdraw its troops from Moldova's breakaway Trans-Dniester province, saying they are there as peacekeepers preventing a resumption of hostilities between the two sides. Still, NATO nations have insisted that because Moscow did not have "host nation consent" from Moldova, it should withdraw its forces from the region. Top Russian officials including Sergei Ivanov, a first deputy prime minister and former defense minister, have repeatedly complained that although Russia's defense budget was cut drastically after the Cold War, the United States and its NATO allies have maintained a high rate of military spending. This contradicted the spirit and intent of arms controls treaties, officials said. They also pointed out that Russia's military budget is now 25 times smaller than that of the nations making up NATO, amounting to only 2.8 percent of the country's gross national product.