Prime Minister Nouri al-Maliki's spokesman, Ali al-Dabbagh, told a news conference Sunday that Maliki appointed a Cabinet-level panel of top defense and military officials to investigate the allegations.

U.S. officials said weapons caches uncovered in recent weeks bore signs of Iranian weapons manufacturers. Iraq officials accused Tehran of not honoring its pledges of non-interference.

"The truth came out; there is evidence of Iranian weapons in Iraq," the spokesman said. "Now we need to document who sent them," The Washington Post reported.

During a meeting with an Iraqi delegation sent to Iran by Maliki, Iranian officials pledged to share intelligence and deter any weapons trafficking across the border.

. Haider Abadi, a Maliki adviser, said Iranian officials told the delegation they were not so naive as to send Iranian-made weapons into a U.S-led fight, and they said Tehran had evidence to counter the U.S. claims, the Los Angeles Times said.