United States Defence Secretary Donald Rumsfeld says he has seen evidence that two Arabic TV networks have been co-operating with insurgents in Iraq.
Rumsfeld is a leading critic of Arabic news channel
He said both al-Arabiya and al-Jazeera had been in "close proximity" to attacks against coalition forces, sometimes even before they occurred.
Mr Rumsfeld added that he could not make a final judgement on the issue.
On Monday the US-backed Iraqi authorities banned al-Arabiya - a Dubai-based channel - from Iraq.
The Iraqi Governing Council (IGC) accused the station of inciting murder "through the voice of Saddam Hussein".
On 16 November the channel broadcast a recorded message said to be from the former Iraqi leader calling for new "resistance".
During a news conference at the Pentagon on Tuesday, Mr Rumsfeld declined to say whether he supported the ban.
"From time to time those stations have found themselves in very close proximity to things that were happening against coalition forces before the event happened and during the event," he said.
Asked if US troops in Iraq had evidence that Arab channels were co-operating with the insurgents, Mr Rumsfeld replied: "The answer is yes."
He told reporters that anti-coalition forces had called al-Arabiya and al-Jazeera, a Qatar-based station, to say: "Come and see us, watch us - here is what we are going to do."
However he added: "I'm not in a position to make a final judgement on it."
The channels have carried messages attributed to Saddam Hussein
Both al-Jazeera and al-Arabiya have rejected the charge of collusion with Iraqi insurgents.
In September, the IGC introduced a law banning the media from inciting violence.
It banned al-Arabiya and al-Jazeera television stations from reporting on government activities for two weeks after they broadcast earlier messages purported to be from the ousted Iraqi president.
Last week Mr Rumsfeld described al-Arabiya and al-Jazeera as "violently anti-coalition".