Iran is quietly building a stockpile of thousands of high-tech small arms and other military equipment — from armor-piercing snipers' rifles to night-vision goggles — through legal weapons deals and a U.N. anti-drug program, according to an internal U.N. document, arms dealers and Western diplomats.

The buying spree is raising Bush administration fears the arms could end up with militants in Iraq. Tehran (search) also is seeking approval for a U.N.-funded satellite network that Iran says it needs to fight drug smugglers, stoking U.S. worries it could be used to spy on Americans in Iraq or Afghanistan — or any U.S. reconnaissance in Iran itself.

The United States has a strict embargo on most trade with Iran, which it accuses of supporting terrorist organizations and trying to build nuclear arms (search). It also has imposed sanctions on dozens of companies worldwide over the past decade for supplying Tehran with equipment that could be used for nuclear or conventional warfare.

Much of the military hardware has been hard to hide — sales of tanks and anti-ship missiles by Belarus and China, or helicopters and artillery pieces from Russia have been well documented by U.S. authorities and international nongovernment agencies.

Other weapons are smuggled and may be revealed only by chance — such as the consignment of 12 nuclear-capable cruise missiles delivered by Ukrainian arms dealers to Iran four years ago but divulged by Ukrainian opposition officials only recently.

The smaller weapons and related material Iran is amassing may not be as eye catching. But they are of U.S. concern because of their origin — through U.N.-funded programs or technically advanced western countries — and because they could harm U.S. troops in Iraq, Afghanistan or ultimately Iran (search), which President Bush has not ruled out as a military target.

Iran says it needs the satellite network, high-tech small arms bought on the European arms market and night-vision goggles, body armor and advanced communications gear through the U.N program to fight drug smugglers pouring in from neighboring Afghanistan.

"We need assistance," Pirouz Hosseini, Iran's chief delegate to U.N. organizations in Vienna told The Associated Press, dismissing U.S. fears as "a political stance not based on realities."

But such high-resolution satellite imagery could reveal what U.S. troops in neighboring Iraq and Afghanistan are doing on the ground — or that they could show the Iranians what the United States is seeing as it spies from outer space for evidence of illicit Iranian nuclear activity.

And with Iran suspected of backing insurgents in Iraq, Washington fears some of the equipment bought in Europe or delivered as part of the U.N.-backed anti-drug fight could be used against U.S. troops there, say Western diplomats here who are familiar with U.S. concerns.

Austrian officials with access to counterintelligence information told AP that Iranian diplomats in European capitals routinely focus on securing arms deals. Like the Western diplomats, the officials spoke on condition of anonymity because of the sensitivity of the case.

Just four months ago, U.S. and Austrian authorities arrested two Iranians in Vienna on charges of trying to illegally export thousands of sophisticated American night-vision systems for Tehran's military — a powerful force in the region.

In a more recent — and legal — deal, Iran last month took delivery of hundreds of high-powered armor-piercing snipers' rifles with scopes from an Austrian firm, as part of a consignment for 2,000 of the weapons. Confirming the sale, Wolfgang Fuerlinger, head of Steyr Mannlicher GmbH, told AP that U.S. Embassy officials had expressed concerns the arms could make their way to Iraq for use against American troops.

The Austrian government approved the sales in November after concluding that they would be used to fight narcotics smugglers. While wary of Iran's ultimate purpose, other European countries also have sanctioned similar deals when convinced Tehran would use the equipment to fight the drug trade, said an Austrian official, declining to offer details.

A draft proposal obtained by AP, to create a regional satellite network that would survey Afghanistan, Iran and Iraq is on hold, with Iran shifting it to the U.N. office on drugs and crime after opposition stalled it in the U.N. office on space affairs, also based in Vienna.

"The U.S. and Britain and France had questions as to what the intention and purpose of the proposal is," a senior U.N. official told AP, requesting anonymity because of the sensitive topic. "One of the worries — is it only drugs they are worried about or something they could use to track other things?"

Still, suspect material is reaching Iran in connection with an aid program created in 1996 by the U.N. drugs office, which also provides training, vehicles and other help to fight what is generally acknowledged as a serious drug problem.

An internal U.N. summary of the program lists France and Britain as providing night vision equipment, mobile global positioning systems, computers and body armor to help Iranian anti-smuggler attempts. Iranian officials confirmed such items were shipped. A diplomat familiar with the program described the shipments of sensitive equipment as "likely in the hundreds."

In London, the Foreign Office confirmed 250 night vision goggles were approved by the British government two years ago for use by Iranian border patrols along the Afghan border.

Another shipment of 50 body armor vests and 100 body armor plates was en route as of last week, as part of British help to Iran that's exempt from a strict embargo and arms and related material, said Foreign Office officials.

Diplomats with access to Iranian program material said other exemptions to the British embargo in recent years have included parts originally manufactured for military aircraft engines that Iran said it needed for its oil and gas industries, aircraft instrumentation components and gas turbine parts that also had possible military applications.

American officials in Vienna and Washington refused to comment on the procurements beyond saying the Bush administration is opposed to all efforts by Iran to buy weapons and any other militarily useful equipment.

But the diplomats in Vienna say that American opposition to such procurements is complicated by the fact that even Washington agrees Iran has a drug-smuggling problem.

Afghanistan last year supplied more than 90 percent of the world's opium, the raw material for heroin, the U.N. anti-drug agency says.

While the source of most heroin in the United States is Colombian or Mexican, heroin from Afghan opium — most of it transiting Iran — makes up 90 percent of what's available on Europe's streets, explaining British, French and other European interest in stanching the flow.

Iran says more than 3,000 of its police officers have died in the last 10 years battling drug smugglers, some equipped with machine guns and rocket launchers.

In a report last year, Antonio Maria Costa, head of the U.N. Office on Drugs and Crime, said Iranian intelligence had shown him pictures of a drug convoy of more than 60 vehicles with armed escorts crossing from Afghanistan to Iran.