Locked in a deepening dispute with the United States and its allies over its nuclear program, Iran’s Revolutionary Guard was reported Monday to have test-fired a long-range missile capable of striking Israel and American missile bases in the Persian Gulf.The reported test of the Shahab-3 missile was not the first conducted by Iran, but it came less than a week after President Obama and the leaders of France and Germany used the disclosure of a previously undeclared nuclear plant in Iran to threaten Tehran with a stronger response.Iran says it wants to develop a nuclear capacity for peaceful purposes but many in the west say it is seeking to create a nuclear weapons capability.The test-firing also came days before the first direct contact in years between the United States and Iran at international talks in Geneva, set for Thursday.Iran’s state-run English-language Press the Shahab-3 had been launched as part of a military drill called “The Great Prophet IV.” The test was said to part of an effort to improve Iran’s defenses. Television footage showed a missile being launched from what appeared to be desert terrain, with a plume of flame as it shot skyward. Press TV said Shahab-3 missiles has a range of between 800 and 1,250 miles. Parts of western Iran lie some 650 miles from Tel Aviv.The maneuvers have included other shorter-range missile tests.“Several models of medium-range Shahab-1 and Shahab-2 missiles were tested during the military drill on Sunday night,” Press TV said on its Web site. It quoted the Air Force commander of the Revolutionary Guards, Brig. Gen. Hossein Salami, as saying Shahab-2 missiles could hit targets at between 200 miles and 450 miles from their launch sites. The launching of the Shahab-3 had been expected as part of a range of Iranian missile tests in recent days. There was no indication whether the testing of a long-range missile — often taken in the west as a sign of potential hostile intent by Iran — was timed to coincide with the Jewish holiday of Yom Kippur.In July 2008 the Revolutionary Guards test-fired nine missiles, including at least one that the government in Tehran described as having the range to reach Israel. At the time, state-run news media said the missiles were long- and medium-range weapons, and included a Shahab-3, which Tehran maintains can hit targets up to 1,250 miles away from its firing position. The launchings did not appear to have so far involved its most advanced missile.In May, Iran test-fired a more sophisticated Sejil-2 missile similar to the liquid-fuelled Shahab-3, which it first obtained from North Korea. The solid-fuelled Sejil-2, experts said, can be stored in mountains, transported reassembled, and fired on shorter notice, and thus could be harder for Israel or other nations to target. It unveiled the Sejil missile in a test-firing last November.The Obama administration is scrambling to assemble a package of harsher economic sanctions against Iran over its nuclear program that could include a cutoff of investments to the country’s oil and gas industry and restrictions on many more Iranian banks than those currently blacklisted, senior administration officials said Sunday.