Each supersonic F-35B Lightning aircraft costs £300million. However, it is not known what connection the jets have with the calamitous situation in Ukraine. The supersonic planes can carry 22,000lbs of firepower including eight Paveway laser-guided bombs.
They will be used by both the Royal Air Force and the Royal Navy and so operate from land and sea.
Britain is to get three more stealth jets this year, and seven more in 2023.
There is an expectation that all of the 48 jets will be delivered from the US by the end of 2025.
The US has a very lucrative arms trade with the UK.
The single biggest deal in recent years was the 2006 agreement for the UK to purchase at least 48 F-35B Lightning II stealth fighter jets.
The cost of the first 48, to be procured up to 2026, is currently expected to be £8.6 billion.