The deal is worth up to £1.6bn and will involve recruiting 200 additional staff.

Thales is a French-owned company which is one of Europe’s biggest arms manufacturers.

The order is for lightweight multirole missiles (LMMs) which Ukrainian forces are already using.

Prime Minister Sir Keir Starmer announced the order as he laid out a four point plan to “reach peace and defend Ukraine”.

East Belfast MP and DUP leader Gavin Robinson said the order is “hugely significant” given the “turbulence” in international relations and the acknowledgement of the “skill and ingenuity” of the Thales team.

A £162m contract announced in September last year saw 650 LMMs supplied to Ukraine as an initial order to ramp up production, with the first deliveries in December.

The new order is much bigger: it is worth an initial £1.16bn with the potential for around a further £500m of work to be added in collaboration with a Ukrainian industry partner.

The partner firm will manufacture launchers and command and control vehicles for the missiles in Ukraine.

Robinson said there is no point talking about international principles and values “if you’re not prepared to stand up for them”.

“We’re giving the tools to make sure a sovereign country has the ability to stand against an international aggressor in Russia, a country that decided to walk over the border, destroy cities, villages and towns and kill civilians,” he said.

Robinson added that the defence spend is “encouraging” for the industry and the Northern Ireland economy.

The UK Ministry of Defence (MoD) said it is the largest contract ever received by Thales in Belfast.

The Defence Secretary John Healey said the deal would “help protect Ukraine against drone and missile attacks and help deter further Russian aggression following any end to the fighting”.

The contract has been placed by the MoD’s procurement arm Defence Equipment & Support on behalf of the Ukrainian Government.

It will be funded by a loan underwritten by United Kingdom Export Finance (UKEF) after a deal signed last year to allow Ukraine to draw on £3.5bn worth of support from UKEF to spend with UK industry.