North Korea fired short-range missiles this past weekend, just days after the sister of Kim Jong-un threatened the United States and South Korea for holding joint military exercises. The missile tests were confirmed by two senior Biden administration officials who briefed reporters on condition of anonymity. The Biden administration has been open about its desire to engage the North in negotiations even as the regime has batted away calls for the two nations to talk. In North Korea's first comments directed at the Biden administration, the North Korean leader Kim's powerful sister earlier this month warned the United States to " refrain from causing a stink'' if it wants to "sleep in peace'' for the next four years.Relations between the US and North Korea, once hailed as potentially promising after former President Donald Trump's three meetings with Kim, have been tense with no substantive contact for more than a year.Since Trump's first meeting with Kim in Singapore in 2018, the North has not conducted nuclear or long-range missile tests, although analysts believe they have pressed ahead with their programs on both. And, the North has not given up short- and medium range missile testing.National security adviser Jake Sullivan is scheduled to meet next week with his South Korean and Japanese counterparts for talks about the way forward with North Korea.