The United States has begun moving military forces abroad in preparation for a sustained campaign against terrorists and their supporters.

Ships, planes and troops are on the move worldwide. The Pentagon says the movements are in support of efforts to identify, locate and hold accountable the terrorists responsible for last week's devastating attacks on New York and Washington and those who support and harbor them.

Confirmation of the initial movements came Wednesday from Deputy Defense Secretary Paul Wolfowitz. He said, "There are movements and you will see more movements and I hope everyone understands why we do not want to reveal details of those movements to people who may be trying to figure out what we're about to do next."

Although defense officials are maintaining strict silence about U.S. plans, additional combat aircraft are reportedly being moved toward the Gulf region to bolster air forces already in the region.

Some of the air reinforcements are aboard the USS Theodore Roosevelt aircraft carrier group, which departed Norfolk, Virginia Wednesday, heading east.

Its deployment raises to five the number of aircraft carrier battle groups now at sea. The Roosevelt is accompanied by guided missile cruisers, destroyers and submarines as well as by a three-ship amphibious assault group including over 2,000 Marines.

The positioning of additional forces in the Gulf region could indicate possible plans for a strike into Afghanistan, where suspected terrorist mastermind Osama bin Laden has been based.

But defense officials have made clear the network controlled by Osama bin Laden operates in scores of countries. They are predicting a long series of actions in what they say will be a sustained campaign against terrorism.