The U.S. will send nuclear-armed submarines to South Korea for the first time in more than 40 years, senior Biden administration officials told NBC News. It’s one element of the “Washington Declaration,” an agreement Presidents Joe Biden and Yoon Suk Yeol are expected to sign Wednesday, aimed at protecting South Korea from North Korea amid growing concerns of nuclear threats. Both U.S. and South Korean leaders have taken note of Kim Jong Un’s regime testing ballistic missiles at a higher frequency over the last several months, prompting the U.S. to make “more visible” deterrence efforts, the officials told NBC. The agreement will not put any nuclear weapons in South Korea’s control. Instead, the United States will more frequently deploy military assets like submarines, bombers and aircraft carriers to the peninsula on a temporary basis. But polling shows that much of the South Korean public would prefer the country develop nuclear weapons of their own, a move the U.S. opposes.