Tehran has denied U.S. accusations that Iran's most senior leaders have ordered the delivery of sophisticated roadside bombs to insurgents in Iraq.
An Iranian foreign ministry spokesman, Mohammad Ali Hosseini, said Monday the U.S. charges are "unacceptable" and accused Washington of fabricating evidence.
In an interview with the American television network ABC, Iranian President Mahmoud Ahmadinejad said his country tries to avoid conflict. He said peace would return to Iraq when U.S. and other foreign forces withdraw.
On Sunday, a group of senior U.S. officials in Baghdad showed journalists what they said was proof that Iranian-made roadside bombs were being used against American forces. The officials said the explosives had killed at least 170 coalition troops in Iraq since 2004.
The top U.S. military officer, General Peter Pace, said today that it is clear materials from Iran are involved, but he said he does not know if the Iranian government is complicit.
General Pace, the chairman of the Joint Chiefs of Staff, made his comments during a visit to Australia.
Several U.S. Democratic Party senators expressed skepticism Sunday about the U.S. government's findings, and cautioned the Bush administration to resolve any disputes with Iran diplomatically rather than militarily.
Some information for this report was provided by AFP and Reuters.