Mildenhall could miss out on a major economic boost if investment in the expansion of the RAF base is blocked.
The combined presence of the United States Air Force (USAF) in Mildenhall and Lakenheath brings an estimated £580m to the local economy.
It was announced earlier this year that 24 state-of-the-art aircraft and 900 additional personal were set to arrive at RAF Mildenhall.
However the US Senate has recommended against investment in the base’s expansion.
Washington officials have questioned the rationale of stationing the aircraft at Mildenhall due to its distance to areas of tension in Africa.
Instead the Military Construction and Veterans Affairs and Related Agencies Appropriations Bill 2014 suggests the investment is made in Sigonella, Italy, which has acted as a ‘key launch-pad’ for missions in the region.
The first of 10 Osprey aircraft and 12 Hercules MC-130J Commando IIs arrived in Mildenhall earlier this summer.
US military magazine Stars and Stripes has reported that the Air Force has asked for $66 million for construction at the base.
A spokesperson for the Secretary of the United States Air Force said: “The Air Force is awaiting the outcome of the FY14 Appropriations Bill. We have no additional information at this time.”