America has sent a plane known as the Flying Pentagon, designed to withstand the blast from a nuclear war, to Europe.
The aircraft, known as the “Doomsday” plane, is thought to be part of a fleet of jets travelling with US president Joe Biden as he visits Brussels for talks with other world leaders over the Ukraine war.
The E4-B, a modified Boeing 747, was spotted flying over the English Channel as the stakes over the war were ramped up amid fears that Vladimir Putin could unleash nuclear, chemical or biological weapons.
The US Air Force has four E-4Bs, of which this one, called Nightwatch, is designated as the command-and-control centre in the event of a nuclear attack.
Designed to withstand the electromagnetic pulse from a nuclear blast, the Flying Pentagon would act as an airborne base for the US defence secretary and senior military personnel to conduct operations.
The $200m plane, which can carry a crew of 112, has 18 bunks and six bathrooms, a briefing room, conference room, work areas and executive quarters.
A bubble on the top, called a “ray dome” or “radome”, contains dozens of satellite dishes and antennae that can send orders to any US ship, submarine or aircraft anywhere in the world.
The US authorities tend to remain secretive about the Nightwatch, but it’s known that it has thermal and nuclear shielding, and it can stay airborne for days with aerial refuelling.
Its windows are reported to be covered in wire mesh to protect the crew from any blast.
Ready for take-off at all times, the “Doomsday” plane on Wednesday flew from Washington, crossed over the Atlantic and the English Channel before heading to RAF Mildenhall in Suffolk, according to flight tracking data.
Nato says it will provide Ukraine with equipment to protect against nuclear, chemical, biological and radiological weapons.
Mr Biden has warned of a “real threat” of Russia using chemical weapons, as it did in Syria.
