RAMSTEIN AIR BASE, Germany (AP) _ Defense Secretary Robert Gates tied Iran's government to large shipments of weapons to the Taliban in Afghanistan and said Wednesday such quantities were unlikely without Tehran's knowledge.
Gates' comments, following accusations by a State Department official, were the strongest yet by a Cabinet secretary about Iran's support of the terrorist group in Afghanistan.
Basing his conclusions on new intelligence, Gates said ``given the quantities (of weapons) that we're seeing, it is difficult to believe that it is associated with smuggling or the drug business or that it's taking place without the knowledge of the Iranian government.''
He said that the latest information indicates a ``fairly substantial flow of weapons'' is crossing into Afghanistan.
Undersecretary of State Nicholas Burns told CNN Wednesday that ``there's irrefutable evidence the Iranians are now doing this.''
``It's certainly coming from the government of Iran,'' he said. ``It's coming from the Iranian Revolutionary Guard corps command, which is a basic unit of the Iranian government.''
State Department spokesman Sean McCormack told reporters ``it certainly is hard to believe that the Iranian government isn't involved in some way, shape or form in this.''
Gates and other defense officials would not go as far as Burns did. The Pentagon chief also said he was not as certain about the link to Iran's Quds Force, which is accused of arming and training Iraqi militants.
In April, Gen. Peter Pace, chairman of the Joint Chiefs of Staff, disclosed that Iranian-made weapons intended for Taliban insurgents were intercepted by U.S. forces in Afghanistan. Pace said at the time it was not clear which Iranian entity was responsible for the arms, which included mortars and C-4 plastic explosives.
Gates made his comments to reporters during a visit to Ramstein Air Base in Germany. He stopped at the base to visit injured troops and awarded six Purple Heart medals to wounded service members at the Landstuhl Regional Medical Center.
The secretary then went to Brussels, Belgium, for a meeting of NATO defense ministers.
Gates said he will press allies for more troops, trainers and equipment for Afghanistan.
He has been frustrated by NATO members' slow progress in meeting commitments in Afghanistan. But he said Wednesday several countries recently indicated a willingness to increase the size of their force in Afghanistan or extend the length of their stay.
``I think countries are taking this seriously and so I will continue to press in Brussels,'' Gates said at a press conference at Ramstein.
Senior U.S. officials en route to Germany with Gates said the secretary would make a pitch for countries to send more trainers for the Afghan National Army and police in an effort to help the Kabul government better control its own security.
The officials, who requested anonymity so they could preview the secretary's plans for the NATO session, said coalition forces in Afghanistan need up to four battalions _ or as many as 3,000 combat troops, along with about an equal amount of trainers. Gates has said he would like some NATO and non-alliance nations to contribute some of the training forces.
In addition, NATO allies are trying to assemble training teams that can be embedded with Afghan units.
In February and again in April, Gates exhorted NATO allies to bolster their troop commitments in Afghanistan so the alliance could launch its own offensive against the Taliban and pre-empt what has been an annual spring increase in insurgent attacks.
That offensive got under way with the aid of additional U.S. troops.
During a visit to Afghanistan this month, Gates said NATO's push was making progress. But he said Iranian weapons, responsible for widespread violence and U.S. troop casualties in Iraq, increasingly were showing up in Afghanistan.
In particular, NATO officials said they have found armor-piercing roadside bombs _ known as explosively formed penetrators, or EFPs _ in Kabul, the Afghan capital.
The struggle to pressure NATO countries to live up to their commitments has led Gates to question whether the alliance should continue to mount a 25,000-troop response force.
The U.S. currently has 26,000 troops in Afghanistan, including some 14,000 in the NATO-led force.
Also expected to come up during the NATO meeting is the U.S. proposal to locate missile defense radars and interceptors in eastern Europe.
Russian President Vladimir Putin, in a recent meeting with President Bush, offered an alternative, joint use of a radar station in Azerbaijan.
Asked Wednesday about the proposal, Gates said that he hopes to discuss the matter with Russian officials and ``certainly underscore our interest in exploring with them President Putin's proposal.''
Gates said he is pleased Putin has acknowledged there is merit to missile defense and that Iran poses a problem that must be dealt with through such defensive systems.