“We remain concerned about the prospect of a seventh nuclear test in multiple administrations,” Blinken said. “We know the North Koreans are preparing for such a test. We are extremely careful about that.” Blinken said the United States was “preparing for any eventuality” and was in “very close contact” with partners such as South Korea and Japan “so that they could respond quickly” if the North Koreans carried out such a test. The top US diplomat said the United States was committed to “talking about how we are expanding the scope and scale of combined military exercises for defense and preparedness purposes, training on and around the Korean missile.” “And of course, we want to ensure that we have all the defense capabilities to deal with any possible provocation or aggression coming from North Korea,” he added. Blinken did not give specific details about the adjustments to the US military stance under consideration. In March, the U.S. Indo-Pacific Administration announced that it had ordered “intensified intelligence gathering, surveillance and reconnaissance activities in the Yellow Sea, as well as enhanced preparedness between our ballistic missile defense forces in the area” in response to the firing. North Korea. Last week, U.S. and South Korean fighter jets made a joint flight into the Yellow Sea – a show of strength that came just days after eight North Korean short-range ballistic missiles were fired. “South Korea and the United States have demonstrated their strong capability and willingness to respond quickly and accurately to any North Korean challenges by demonstrating their combined defense capabilities and stance through this combined aviation demonstration flight,” the South Korean Defense Ministry said. . South Korean Defense Minister Li Yong-soup said Sunday that his country “will strengthen its capacity to better implement the extended US deterrent and dramatically strengthen its … military response capabilities to prevent nuclear and North Korea’s missile threats. “ North Korea’s “repeated missile challenges” were “quality and quantity,” Li said, adding that this and preparations for a nuclear test were a “serious challenge that threatens peace and stability.” Despite continuing challenges from Pyongyang, Blinken reiterated on Monday that the United States remains “committed to a diplomatic approach”, ready to engage with North Korea unconditionally and “has no hostile intentions” towards the nation. “But our unconditional engagement so far has not received a response from North Korea,” he said. “In fact, the only answer we’ve seen so far has been this multiplicity of missile tests.” CNN’s Simone McCarthy, Heather Chen, Brad Lendon, Yoonjung Seo, Ellie Kaufman and Barbara Starr contributed to this report.