President Joe Biden is meeting with two close U.S. allies to announce that Australia will buy nuclear-powered attack submarines from the U.S. to modernize its fleet. The agreement comes as concerns grow about China’s influence in the Indo-Pacific region. Biden flew to San Diego on Monday for talks with Australian Prime Minister Anthony Albanese and U.K. Prime Minister Rishi Sunak on their 18-month-old nuclear partnership. In a three-day trip to California and Nevada, Biden will also discuss gun violence prevention during a stop in Monterey Park, California, and his plans to lower prescription drug costs in a visit to Las Vegas.