Iran's elite Revolutionary Guards test fired its new Russian defense missile system Wednesday near the strategically important Strait of Hormuz, state radio reported. The two-day maneuvers are Iran's second since the United Nations Security Council approved economic sanctions against it Dec. 23, which ban selling to Iran materials and technology that it could use in its nuclear and missile programs. As tensions rise over Iran's nuclear standoff with the West, the United States and Iran have pursued an escalating series of military moves, with Washington sending a second aircraft carrier battle group to the region and Iran responding with more frequent maneuvers. The Revolutionary Guards' began the games Wednesday in the Persian Gulf and Oman Sea, which flank the strait, through which some 20 percent of the world's oil transits daily. The goal of the maneuvers, dubbed Saegheh and Badr, is to improve the "defense, stamina and operation" of participating units, state radio reported. The first word of the games' name means lightening, while the second refers to a decisive battle in the early days of Islam. Iran announced in January that it had received the Tor M-1 Russian air defense missile system, though it did not say when the weapons had arrived. Moscow had said previously it would supply 29 of the systems to Iran under a US$700 million (â‚¬539 million) contract signed in December 2005. Iran in January launched three-day military maneuvers, including short-range missile tests on its mainland. "It's not uncommon for us to see them saber-rattle," said Lt. Cmdr. Charlie Brown of the US Navy's Fifth Fleet, based in Bahrain, just across the Gulf from Iran. "We don't want any country to miscalculate about our commitment to stability and security here," Brown said, declining to comment on the missile tests themselves. "We hope other nations in the region wouldn't take action to harm that."