In the face of mounting international pressure to suspend its nuclear activity, Iran flexed its muscles on Wednesday and test-fired its most advanced ballistic missile, capable of hitting Israel and parts of Europe. The missile tested, according to Iranian reports, was an upgraded version of the Sajjil 2, a sophisticated ballistic missile that has a range of close to 2,000 kilometers, can carry a nuclear warhead and is powered by a solid-fuel propellant which gives it greater accuracy and range. With solid fuel, the missile can be stored in underground silos, making it more difficult to detect before launch. "This missile can threaten Europe," one Israeli defense official said. "If Israel were their only enemy, why would they need missiles that can reach Europe?" According to the official, the Super Green Pine Radar, which works in conjunction with Israel's Arrow missile defense system, detected the launch of the Sajjil, as did the US-manned X-Band Radar located in the Negev. "We closely follow what happens in Iran," the official said, adding that the IDF was familiar with the Sajjil, which had been tested for the third time on Wednesday. The missile, officials said, was still in final development and testing stages and would soon enter mass production. The test stoked tensions between Iran and the West, which is pressing Teheran to rein in its nuclear program. British Prime Minister Gordon Brown said it showed the need for tougher UN sanctions on 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," Brown said after talks with UN chief Ban Ki-moon in Copenhagen. In Washington, Defense Department press secretary Geoff Morrell called the launch "provocative" but said the technology had not been "particularly different than anything we've seen in the past." "Obviously, it is another example of provocative actions on the part of the Iranian government that do nothing to instill any degree of confidence in its neighbors that it has peaceful intentions... that they are serious about resolving some of these issues in a peaceful, diplomatic way," Morrell told a Pentagon press conference. Iranian state television broke the news in a one-sentence report accompanied by a brief clip of the test, showing the missile rising from the launch pad in a cloud of smoke. Iranian Defense Minister Gen. Ahmad Vahidi vowed that the Sajjil-2 would be a "strong deterrent" against any possible foreign attack. He said the new version can be fired more quickly and flies faster than previous ones, making it harder to shoot down, though he did not give further details. "Given its high speed," he said, speaking on state TV, "it is impossible to destroy the missile with anti-missile systems because of its radar-evading ability." The name "Sajjil" means "baked clay," a reference to a story in the Koran in which birds sent by God drive off an enemy army attacking the holy city of Mecca by pelting them with stones of baked clay. The Sajjil-2 was first tested in May. Iranian officials touted it as a breakthrough over the Sajjil-1 unveiled months earlier, saying the new missile had a more sophisticated navigation system. The Sajjil-2 was tested a second time in September. Uzi Rubin, an Israeli expert and former defense ministry official, said the test did not show any new advances in technology. But "the fact that they are capable of carrying out three launches in a year is significant, because it means the Iranians are investing a lot of money in this," he told Israel Television. "They are in a hurry and they intend to make this missile operational as quickly as possible." "From the amount of raw material caught lately on the way to Iran, it can be understood they intend to produce hundreds of these and they intend to use them instead of long range Katyushas," Rubin said. Iran has dramatically accelerated its domestic missile program in recent years, part of a bid to depict itself as a military and technological power and reduce its past reliance on purchases abroad. The missile program has raised deep concerns in Israel and the West, though experts are skeptical over some of Iran's claims of advances. But equally important is the political message, said Washington-based security analyst Alex Vatanka. "One signal is very clear - they are saying Iran will not negotiate with the West from a position of weakness. They are saying: If you think sanctions and threats are something to worry us, then you are mistaken," said Vatanka, with the intelligence analyst group Jane's. "The message from Iran today is that Teheran can do more. Iran's arm is long," he said. Nuclear negotiations between Iran and the West have been deadlocked for months, with Teheran equivocating over a UN-drafted deal aimed at removing most of its low-enriched uranium from the country so it would not have enough stockpiles to produce a bomb. The UN nuclear watchdog last month sharply rebuked Iran for refusing to halt uranium enrichment, and Washington has warned that Iran is running out of time to accept the deal or face new sanctions. AP contributed to the report.