Defense ministers from the three nations signed the accord in Tokyo on Thursday.

That sets in motion the Global Combat Air Programme.

An early mock-up of the plane has previously been shown off by UK defense giant BAE Systems.

It's intended to create a next-generation stealth combat aircraft, capable of defeating the latest jets from Russia or China.

Officials says its radar will provide 10,000 times more information than current systems.

Speaking in Tokyo, British defense minister Grant Shapps said the need for the new jet was clear:

"The risks and problems from Europe to the Indo-Pacific are clear for all to see. And so it is enormously important that we join together across our nations to produce this kind of security for our skies."

The new plane is meant to be in service by 2035.

Development efforts will be headquartered in the UK, with the first chief executive for the project to come from Japan.

Besides BAE, major firms involved include Italy's Leonardo and UK jet engine maker Rolls-Royce.

Reuters has previously reported that Japanese firms including Mitsubishi Heavy Industries will also play a big role.

The parliaments of each country must now ratify the agreement.