A nuclear-powered U.S. aircraft carrier, the Theodore Roosevelt, arrived in South Korea’s port city of Busan on Saturday for joint military exercises this month with the host nation and Japan, the Yonhap news agency said. The leaders of the three nations agreed at a Camp David summit in August 2023 to hold annual military training drills as they condemned China’s “dangerous and aggressive behaviour” in the disputed waterway of the South China Sea. Russian President Vladimir Putin visited North Korea this week for the first time in 24 years and signed a deal with leader Kim Jong Un that included a mutual defence pledge. It was one of Russia’s most significant moves in Asia for years, which Kim described as amounting to an “alliance”. The visit comes seven months after a South Korea trip by another U.S. aircraft carrier, the Carl Vinson, in a show of extended deterrence against the North’s nuclear and missile programmes.