Some 1,200 extra US personnel will be based at RAF Lakenheath when the US Air Force's stealth fighter squadrons arrive at the base.

As well 21st Century combat technology, the jets will also bring a major boost to the region's economy when they touch down in two years' time.

Work is under way on the buildings which will house them. A squadron operations building will include an aircraft maintenance unit with separate administration, amenity, lecture theatre and classroom areas.

There will be similar spaces for two squadrons, with accommodation for each mirrored on either side of the building.

Work has also started on the construction of a flight simulation facility to train the next generation of F-35 pilots.

Defence Infrastructure Organisation (DIO) programme director Keith Maddison said: "We are pleased with the progress achieved at the base since the ground breaking event. The site is changing and improving every day and it is exciting to see key buildings like the flight simulator and the maintenance unit beginning to take shape.

"We are proud to be playing a central role in preparing RAF Lakenheath to become the first permanent international site for US Air Force F-35s in Europe."

Col Jason Camilletti, US Air Force 48th Operations Group commander, said: "We appreciate the collaboration with our teammates to deliver these world-class facilities.

"By creating synergy in the training and development of our aircrew, maintainers, and support personnel, this shared space will ensure we'll continue to be ready to secure the sovereign skies above."

At the height of construction, it is expected that there will be up to 700 people on site supporting the programme. The investment will also provide wider benefits both to the project and to the local economy.

Construction materials from the demolished buildings have been reused on site for car parks, roads and other hard standing areas. DIO awarded a contract worth £160m to the Kier VolkerFitzpatrick joint venture in November to deliver critical infrastructure at the Suffolk air base.

Similar major modernisation work was carried out RAF Marham, in readiness for the F-35's arrival there.