FBI Director Robert Mueller on Wednesday detailed the next steps of his organization's restructuring — ongoing since the days after the Sept. 11, 2001, terrorist attacks — including a new business-side position and a weapons of mass destruction division.

Mueller said the new changes will be good for both the function of the agency and its finances.

"We are better able to have leadership from the top down. ... We can align our personnel and our budget," Mueller told reporters during a briefing at Justice Department headquarters.

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The changes are the latest in a series that began with the immediate restructuring after Sept. 11 of the domestic intelligence bureau to respond to terror threats and the founding of the bureau's intelligence-gathering program.

Part of the so-called "Phase 3" changes will include a new position that Mueller said is aimed at maintaining the "business side of the house" of the agency. That position will be filled by new Associate Deputy Director John Ford, who will be in charge of personnel, budget, administration and infrastructure capabilities. Mueller appointed Ford, a career FBI employee, to the position on Tuesday.

The new post is meant to give Mueller and Deputy Director John Pistole more time to deal with "programmatic" issues. Mueller said that terror is still a problem for this country. While the command structure of Al Qaeda, the terror network that was operating inside the United States before the 2001 attacks, has been damaged by domestic efforts since the initial reorganization, it is still capable of attacking within U.S. borders, he said.

Part of the reorganization calls for the FBI to be split into five branches, the leaders of which have the title of executive assistant director. The five branches are under the headings of national security, criminal investigations, human resources, science and technology and the Office of the Chief Information Officer.

The National Security Branch is hosting a new FBI function in its weapons of mass destruction directorate. Vahid Majidi, a former official at the Justice Department and chemistry division leader at the Energy Department's Los Alamos National Laboratory, will be in charge of the directorate, which will prepare against domestic WMD attacks.

Majidi said his office seeks to prevent biological attacks by U.S. mail and nuclear detonations, among other threats. Federal authorities have been long thwarted in its efforts to identify the source of the anthrax mail attacks in 2001 that killed five people.

One of the more frightening possibilities of nuclear attack on U.S. soil is a "dirty bomb," or a simple explosive device that could be detonated to spread radioactive material. Terror suspect and former Chicago gang member Jose Padilla was initially implicated in a dirty bomb plot, but a Miami-based federal indictment only mentions alleged terrorist training activities.

"I think it is fair to say that anyone who is concerned about the safety of this country and the future, their concern is weapons of mass destruction and particularly weapons of mass destruction in the hands of terrorists," Mueller said.

"This is a reflection of focusing our efforts on preventing a weapon of mass destruction being used in the United States," he said.

He said, however, that he was not aware of any specific threats of such an attack.

Though no such threats are imminent, Philip Mudd, the No. 2 official in the FBI's new national security branch — one of five new branches — said a growing number of U.S. residents share Al Qaeda's view that "killing of innocents to meet an end is acceptable."

He said he doesn't believe those people are actually affiliated with Al Qaeda, but they are definitely willing to use their modus operandi. For instance, last month authorities broke up an alleged plot to attack the Sears Tower in Chicago and other prominent buildings throughout the country.

Seven men were arrested but prosecutors have said they have no apparent ties to the terror group behind the Sept. 11 attacks.

FOX News' Ian McCaleb and The Associated Press contributed to this report.

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