TEHRAN (Reuters) -- Iran successfully test-fired a long-range, improved Sejil-2 missile today, state television reported, in an announcement that added to tension with the West.
British Prime Minister Gordon Brown said the launch underlined the case for tougher sanctions against Tehran.
Al-Alam, Iran's Arabic-language satellite television, said the two-stage, solid fuel Sejil missile had a longer range than the Islamic republic's Shahab model.
Iranian officials have in the past said the Shahab-3 missile can reach targets up to 2,000 kilometers away. Such a range would put Israel and U.S. bases in the Persian Gulf within reach.
The missile test coincides with increased tension over Iran's nuclear program, which the West fears is aimed at making bombs. Iran denies the charge.
Neither Israel nor the United States have ruled out military action if diplomacy fails to resolve the dispute. Iran has vowed to retaliate for any attack.
State television showed a missile launched from desert-like terrain soaring into the sky with a long vapor trail.
Press TV, Iran's English-language television station, said of the test: "The missile hit its target."
"Iran successfully tests optimized version of Sejil-2 missile," it said in a breaking-news headline.
The test came a day after the U.S. House of Representatives approved legislation to impose sanctions on foreign companies that help supply gasoline to Iran, a measure lawmakers hope would deter Tehran from pursuing its nuclear work.
Iran has repeatedly shrugged off the impact of such punitive measures, that include three rounds of limited UN sanctions since 2006.
In Copenhagen, Britain's Brown said after meeting UN Secretary-General Ban Ki-moon: "I have expressed to him and he has also expressed concern about the test of a long-range missile by Iran.
"This is a matter of serious concern to the international community and it does make the case for us moving further on sanctions."
"We will treat this with the seriousness it deserves."
In September, Iran test-fired missiles that a commander said could reach any regional target. The White House branded those tests "provocative" and reiterated demands that Iran come clean on its nuclear program.
Washington suspects Iran is trying to develop nuclear-bomb capability and has previously expressed concern about Tehran's missile program. Iran, a major oil producer, says its nuclear work is solely for generating peaceful electricity.
The United States and five other major powers said on December 15 that a planned meeting on Iran's nuclear program will not take place this year because of scheduling conflicts, although consultations will continue by telephone.
In October, negotiators offered a deal under which Iran would send most of its low-enriched uranium abroad for further enrichment. However, Tehran has backed away from it, raising the prospect of additional sanctions.