"To make the system work, the right hand of enforcement must know what the left hand of visa application and processing is doing at all times," the president's homeland security adviser, Tom Ridge, told the Senate Judiciary Committee.

The House in April voted to break up the INS into separate agencies dealing with border enforcement and new citizenship. That vote came before the White House effort to move the entire agency into the proposed Cabinet-level department.

Some lawmakers said it sends the wrong message to combine the job of processing legitimate immigrant visas with that of border control in the new department.

"Better to have a comprehensive approach and one agency over which there is controlling legal authority rather than dividing the responsibility between two or more Cabinet agencies," Ridge said.

Other agencies being transferred have different missions that have nothing to do with homeland security, such as the Coast Guard's work with marine fisheries and boating safety. Ridge said the administration wants to keep all of those agencies intact.

"To try to segregate and separate them would not guarantee the kind of reform and improvement we would all seek," he said.

At House Agriculture Committee hearing, farm groups and many lawmakers questioned the wisdom of shifting the Agriculture Department's plant and animal health division. It deals with eradication of pests and diseases affecting the food and fiber supply, ranging from cotton boll weevils to citrus canker.

"The reality is that even in wartime, cows must be milked," said Rep. Charles Stenholm, D-Texas.

Ridge said the Bureau of Alcohol, Tobacco and Firearms and other agencies should remain where they are. Although they do have some anti-terrorism duties, "their primary mission seems to be outside that venue," Ridge said.

He expressed confidence in changes at the FBI and CIA, investigative agencies that are to remain independent from the new department despite criticism they failed to provide any warning before the Sept. 11 attacks.

"It is essential that reforms in the FBI and the CIA must continue," said Sen. Orrin Hatch of Utah, the committee's top Republican.

Ridge cited steps by the FBI and CIA since Sept. 11, such as better sharing of intelligence information, as evidence they were moving the right direction. He was responding to a question from the committee chairman, Sen. Patrick Leahy, D-Vt., if a new terrorism investigative agency were needed.

Ridge said he thought FBI Director Robert Mueller was "making very aggressive and very positive steps."

The administration wants to combine 100 federal entities with 170,000 employees and total annual budgets of at least $37 billion into one department * all without spending any extra government money. President Bush does not plan to ask for any money for the new department until the 2004 budget year, which many lawmakers say is not realistic.

Agreeing with them was Comptroller General David Walker, head of the General Accounting Office, the investigate arm of Congress.

Despite possible savings in the long term, he told a Senate Judiciary subcommittee Tuesday, "there will be certain transition costs in the near term associated with setting up the new agency."

Walker also said it will take time to create the department. The White House is encouraging swift passage of legislation setting up the department, and lawmakers are rushing to pass initial versions of the plan by the end of July. But complaints about specific pieces have arisen.

"The magnitude of the challenges that the new department faces will clearly require substantial time and effort, and will take extra resources to make it fully effective," Walker said.

Some lawmakers, health advisers and GAO experts questioned whether public health dangers such as a virulent outbreak of influenza could take a back seat to bio-terrorism threats under in the new department.