The White House said Wednesday the U.S. will share nuclear submarine technology with Australia in a new trilateral military partnership. The coalition is known as AUKUS, short for Australia, United Kingdom and United States. Its formation comes as President Biden continues to pressure U.S. allies to take a more aggressive military posture toward China. British Prime Minister Boris Johnson joined Australian Prime Minister Scott Morrison and President Biden at a virtual summit Wednesday.

Prime Minister Boris Johnson: “And the first task of this partnership will be to help Australia acquire a fleet of nuclear-powered submarines, emphasizing, of course, that the submarines in question will be powered by nuclear reactors, not armed with nuclear weapons. And our work will be fully in line with our nonproliferation obligations.”

The U.S., U.K. and China are among the nine nations known to possess nuclear weapons. None of them have signed or ratified the Treaty on the Prohibition of Nuclear Weapons. Neither has Australia, which says it supports the retention and potential use of U.S. nuclear weapons on its behalf.