WASHINGTON, July 8 (Xinhua) -- The United States panel probing the September 11 terror attacks complained Tuesday that some government departments, including Defense and Justice, have not cooperated fully with the investigation.

　　Republican Thomas H. Kean and Democrat Lee Hamilt on, chairman and vice chairman of the 10-member commission, said government cooperation is important because it will determine whether the panel can write a thorough report by its May 2004 deadline.

　　"The task in front of us is monumental, and time is slipping by," said Kean, a former governor of New Jersey.

　　The commission has requested 26 briefings and made 44 requests for documents, which cover millions of pages, from 16 government agencies. There was no response to requests relating to North American Air Defense Command (NORAD), the air defense network shared by the United States and Canada, the Joint Chiefs of Staff, and other Defense Department components, the commission said.

　　Kean and Hamilton said though the commission has access to "a wide range of sensitive documents" from the White House and the National Security Council, "conditions have been imposed, in some cases, with respect to our access to and usage of materials."

　　The commission also said the Central Intelligence Agency (CIA) has not responded quickly to the panel's requests for internal documents on management and resources.

　　The commission said within the Department of Homeland Security, elements of the former Immigration and Naturalization Service "have been slow in providing briefings."

　　The commission was created by legislation after families of victims of the Sept. 11 attacks demanded a broad probe. Some 3,000 people were killed in the Sept. 11 attacks on the World Trade Center and the Pentagon in 2001. End