The U.S. Central Command has been closely monitoring and updating plans for an attack on Iran.

Although the Pentagon has emphasised that the process is routine for the military, the muscular rhetoric coming from President George W. Bush and Sec. of State Condoleezza Rice has served to underscore the U.S. attentiveness to the range of threat scenarios in the Middle East and other regions.

"The Iranians just need to know that the free world is working together to send a very clear message: Don't develop a nuclear weapon," President George Bush said on Wednesday. "And the reason we're sending that message is because Iran with a nuclear weapon would be a very destabilizing force in the world."

The Bush administration has stressed that the United States was not planning to attack Iran, Middle East Newsline reported. But administration officials have refused to rule out such a prospect amid Teheran's insistence in continuing its nuclear program.

Officials said Central Command, responsible for Iran and the surrounding region, has not been under any alert or heightened state of planning regarding Teheran. They said Central Command has maintained a close watch on Iran, particularly regarding threats against the U.S. military presence and the interim government in neighboring Iraq.

"What we are doing right now, our focus is on the day-to-day operations, the tactical operation, and I'm talking in regards Iran," Lt. Gen. Lance Smith, deputy chief of Central Command, said. "Our focus is on what are they doing, you know, to try and influence what's going on in Iraq."

Central Command has examined such Iranian threat scenarios as the deployment of the Shihab-3 intermediate-range missile, the military buildup along the Iraqi border and Iran's nuclear weapons program, officials said.

Iran has repeatedly threatened to attack U.S. targets in the Middle East amid Washington's campaign to force Teheran to suspend uranium enrichment and the production of plutonium.

But officials said Central Command has so far not played a key role in U.S. policy on Iran. They said the State Department has assumed responsibility for a diplomatic effort to recruit an international coalition against Teheran.

"I'm not spending any of my time worrying about the nuclear proliferation in Iran," Smith said. "At this stage, it seems to me that the diplomatic efforts that Secretary [of State Condoleezza] Rice is engaged with and what she's doing in her discussions with the European allies is adequate for our needs."

Still, Central Command has continued with an update of war plans regarding Iran and the rest of the region. Smith said the update was normal and did not reflect any instruction from the White House.

"We have a requirement on a regular basis to update plans," Smith said.

"We try to keep them current, particularly if our region is active. But I haven't been called into any late-night meetings at, you know, 8 o'clock at night, saying, 'Holy cow, we got to sit down and go plan for Iran.'"

Officials said the Defense Department has discussed a U.S. military response to Teheran's nuclear weapons program as well as ordered increased reconnaissance of Iran. They said the Pentagon has held interagency meetings and simulations of air attacks on suspected Iranian nuclear facilities amid an assessment that Teheran could be ready to assemble nuclear weapons by 2007.

At the same time, the Bush administration has stressed that the United States was not planning to attack Iran. But administration officials have refused to rule out such a prospect amid Teheran's insistence in continuing its nuclear program.