WASHINGTON (CNN) -- Joint Chiefs of Staff Chairman Gen. Peter Pace appeared Tuesday to question Bush administration assertions that the Iranian government is supplying weapons to Shiite militant groups in Iraq.

"We know that the explosively formed penetrators are manufactured in Iran," Pace told Voice of America during a trip to Australia about what senior military officials call EFPs.

"What I would not say is that the Iranian government per se knows about this. It is clear that Iranians are involved and it is clear that materials from Iran are involved, but I would not say, based on what I know, that the Iranian government clearly knows or is complicit," Pace said.

White House spokesman Tony Snow on Tuesday portrayed the general's comments as in line with the administration's viewpoint.