While the UK doesn’t currently own any hypersonic missiles… the U-S and Australia have an existing joint programme to develop the weapons.
Britain says this new partnership is aimed at strengthening defence capabilities and says there are no plans to develop its own.
Officials also say this announcement is not related to Russia’s use of the weapons in Ukraine but rather an investment in how to defend against the missiles.
Under the deal, the AUKUS countries will develop hypersonic missiles, and missile defence systems and radars.
Western allies are currently in a race with China and Russia to develop hypersonic missiles.