U.K. Prime Minister Rishi Sunak has announced an extra $6 billion in defense spending over two years to replenish ammunition stocks, modernize the UK’s nuclear submarine program and fund the “next phase” of AUKUS, a security pact struck between the three nations in 2021. The details of the AUKUS program will be revealed Monday in San Diego during a joint news conference between Sunak, US President Joe Biden and Australian Prime Minister Scott Morrison. The summit is expected to be a major step in strengthening the countries' defense partnership and countering China's growing military presence.