WASHINGTON – Iran claims to have tested a missile that could reach Israel, a move that has raised concerns in Washington and added to already unusually high tensions in the region.

Iran’s official news wire, the Islamic Republic News Agency, quoted a powerful former president, Akbar Hashemi Rafsanjani, as saying the latest tests of the Shahab 3 missile could hit targets at ranges of 1,250 miles. Mr. Rafsanjani was quoted as saying, “If the Americans attack Iran, the world will change…they will not dare make such a mistake.”

If Iran’s military has in fact successfully tested a missile that could travel 1,250 miles, it could deepen the threat of a nuclear attack against the Jewish state. Both Israel and America believe Iran’s uranium enrichment activities are in preparation for a nuclear weapon. And Iranian officials in the last week have become more bellicose in their rhetoric, warning the Iraqis about the possibility of Israeli spies and promising brutal retaliation against Israel if the Jewish state attempts to bomb any Iranian reactors.

On Monday, Prime Minister Sharon said vaguely that he was taking “measures to defend” Israel from Iranian aggression. His national security adviser last month used the language of the Israeli prime minister who took out Iraq’s nuclear program at Osirak in 1981, saying that in November, Iran would reach “the point of no return” for its nuclear program. At the end of this month, the International Atomic Energy Agency is slated, yet again, to consider whether Iran’s vast program is for peaceful energy purposes as its leaders have repeatedly said it is.

At the State Department yesterday, deputy spokesman Adam Ereli said, “We view Iran’s efforts to further develop its missile capabilities as a threat to the region and to the United States’s interests, and all the more so in light of its ongoing nuclear program.”

The deputy director of the Washington Institute for Near East Policy, Patrick Clawson, was more blunt. “The disturbing question we have to ask is what warhead do they intend to put on this missile and it is more and more likely they would put an unconventional warhead on this missile,” he said. “Missiles can always use improvement, there are lots of things that could be done to make the missiles more effective.”

If the Iranians are correct that the new missile could cover 1,250 miles, they could threaten the entire Gulf region. Not only could missiles launched from inside Iran hit Israel, but the mullahs would have the ability to strike American Navy vessels securing the Persian Gulf sea lanes, the route necessary for the delivery of oil to most of East Asia.

At the same time, one Western diplomatic source told The New York Sun that he doubted the Shahab-3 missile could reliably be launched at a target nearly 1,300 miles away.

“We know the tests from August for the Shahab-3’s were largely unsuccessful,” this source said. Mr. Clawson said yesterday, “Missiles can always use improvement, there are lots of things that could be done to make the missiles more effective.”

At yesterday’s press briefing, Mr. Ereli said, “It’s well-known that Iran has had an active missile program for almost two decades, that Iran has been in the late stages of developing the Shahab-3 medium-range ballistic missile and that is has been working on longer range systems.”

He added, “These kinds of long-range missiles which have been the subject of reports has been an active area of Iranian weapons development for some time, has been a concern of ours for some time. And international cooperation with like-minded countries is important to take steps to address these efforts, and that’s where we’re focusing our efforts.”

On Sunday, Iran’s Foreign Ministry rejected a proposal floated last Thursday by Democratic presidential nominee, Senator Kerry.

Mr. Kerry proposed pursuing a diplomatic deal with Iran similar to the one President Clinton forged with North Korea in 1994 that would provide the Islamic republic with nuclear fuel in exchange for a promise to dismantle its nuclear fuel cycle. The spokesman for Iran’s Foreign Ministry asked how he could trust outside powers to continue to keep their word to supply the fuel.

Israel has long said that shorter-range Iranian missiles and rockets have been provided to Hezbollah in southern Lebanon that are capable of hitting Israeli cities on orders from Iran. Most experts believe the longest-range missiles the Iranians currently have can travel approximately 800 miles.