Over the past two months, the number of U.S. servicemen and women in the region has soared to around 50,000.
The troops are joining around 400 military aircraft and at least three aircraft carriers already in the Gulf.
The deployments have been done discreetly. Analysts said this is now the biggest massing of U.S. military might in the region since the 1991 Gulf War.
The number troops re-enforce the thought that U.S. forces "may" be preparing for a mass ground invasion of Iraq.