SEOUL, South Korea — North Korea launched multiple projectiles off its east coast on Monday in the country’s second weapons test in a week, the South Korean military said.

       The projectiles were launched from Sondok, in South Hamgyong Province on the North’s east coast, and flew northeast before falling in waters between the North and Japan, South Korean defense officials said. Some projectiles flew up to 124 miles, they said.

       The launches appeared to be part of a live-fire winter military training drill that included various types of multiple-rocket launchers, they said. They provided no further details.

       The office of South Korea’s president, Moon Jae-in, said it was a “large-scale” military drill. It followed other North Korean military exercises on Feb. 28 and March 2. The South Korean military expressed “strong regret” over the drills, which it said raised tensions on the Korean Peninsula.

       On March 2, North Korea launched two short-range projectiles off its east coast, according to South Korean officials. It was the country’s first weapons test in three months and a return to its provocative behavior a year after a failed summit meeting between the North’s leader, Kim Jong-un, and President Trump.

       Mr. Kim was in attendance at last week’s weapons test, which took place near Wonsan, a port town east of Pyongyang, the North Korean capital. Photos in the North Korean state media later showed the launching of what the North called a “super-large multiple rocket launcher,” a new weapon developed to target South Korean and American military bases farther from North Korea’s border with the South.

       South Korean officials accused the North last week of raising military tensions.

       Mr. Kim’s sister and policy aide, Kim Yo-jong, called the South Korean reaction “idiotic.” But Mr. Kim on Wednesday sent a personal letter to South Korea’s president, Moon Jae-in, expressing his best wishes for the South in its battle against a coronavirus outbreak and reconfirming his “unwavering friendship and trust toward President Moon,” the South Korean presidential office said.

       Mr. Kim also expressed “his candid thoughts and positions on the situation surrounding the Korean Peninsula,” Mr. Moon’s office said without elaborating.

       North Korea’s relations with the United States and the South have chilled since a summit meeting last February in Vietnam between Mr. Kim and Mr. Trump collapsed over differences regarding how to denuclearize North Korea and when to ease American-led U.N. sanctions.

       In a meeting of his ruling Workers’ Party at the end of December, Mr. Kim indicated that he had all but abandoned hopes for diplomacy with Washington, and that he had ordered his country to brace for a prolonged standoff with the United States and to endure sanctions. In that meeting, Mr. Kim also said his country no longer felt bound by its self-imposed moratorium on testing nuclear weapons and long-range ballistic missiles and that the world would witness a new strategic weapon “in the near future.”