Defense Secretary Robert Gates and other senior defense officials have said it is too soon to judge the significance of the three-month decline in the use of explosively formed penetrators (EFPs) and other Iranian made weapons.

But a deputy corps commander in Iraq, Major General James Simmons, said Thursday that Iran appears to be living up to a commitment to Iraqi Prime Minister Nuri Al-Maliki to stop the flow of the weapons into the country.

Senior defense officials in Washington suggested that Simmons' conclusion was overstated, but said there was little doubt that the flow of weapons from Iran to Iraq has slowed or stopped.

Armor-piercing EFPs have turned up in recently captured weapons caches in Iraq, but those are believed to pre-date a pledge Iranian leaders made to Maliki during a visit to Tehran in August, officials have said.

Attacks involving EFP's dropped from 99 in July to 53 in October.

What remains unclear is whether the Iranians decided to stop the flow of weapons, and if so why, and whether it points to a broader change in direction by Tehran or just a temporary respite.

"We're not there yet," a senior US defense official said, explaining that more time was needed to assess the development and its implications.

"We certainly hope that the Iranians have decided to fulfill their commitments to the Maliki government," the official added.

The developments in Iraq come as the Bush administration is trying to ratchet up international pressure on Iran on the nuclear front.

At a White House meeting Friday with Japanese Prime Minister Yasuo Fukuda, Bush said international pressure "must, and will, grow" on Iran to halt its uranium enrichment program.

"The prime minister and I agree that a nuclear-armed Iran would threaten the security of the Middle East and beyond. Our two nations are united in our efforts to change the regime's behavior through diplomacy," Bush said.

Senior defense officials said the nuclear issue is the administration's primary concern.

But a turnaround on Iraq by Tehran would be a major break for the US military, which is banking on a sustained reduction of violence in Iraq to undertake a phased drawdown of US forces.

Wary that it might be too good to be true, US officials point to what they say is Iran's record of arming and training "special groups" of Shiite extremists that have killed US forces.

"That they have had a negative influence in the past, that they have assisted in the killing of coalition, Iraqi and American soldiers is a matter of fact," said a senior US military official, who spoke on condition of anonymity.

"We want them to have a more peaceful, positive and productive role," he said. "But we have not seen an indication that the more positive role that they have asserted they will take has in fact happened."

The official said the military will look for cumulative evidence over time that a change has occurred.

"It's not to say that some positive movement isn't occurring. It very well could be or it's just too soon to tell with any kind of definition. We just see no indication that there has been that kind of movement by them," he said.

In the meantime, US military leaders have toned down their rhetoric on Iran.

Earlier this month, the military in Iraq released nine Iranians, including two members of the Iranian Revolutionary Guards-Qods Force, after deciding they no longer posed a threat or were of intelligence value. Eleven others remain in US custody in Iraq.

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