While the U.S. conducts bomber flights in the region on a routine basis, Tuesday's joint training mission is particularly noteworthy as it comes just one day after the death of Otto Warmbier - a 22-year-old American who was detained in North Korea for 17 months.
Two US B-1 bombers flew over the Korean peninsula Tuesday in a planned bilateral training mission with Japanese and South Korean F-15 fighter jets, a US military official told CNN.
Analysts said his death is likely to cast a shadow on relations between the United States and North Korea and compound efforts by South Korea's new liberal president to improve ties with the North.
But for now, "we must continue to strengthen our sanctions and pressure on North Korea", he said.
The Hamilton County Coroner's Office was still conferring on Tuesday with doctors at a Cincinnati hospital who were treating Otto Warmbier, 22, before reaching any conclusions about his death a day earlier, investigator Daryl Zornes said. "We can not know for sure that North Korea killed Mr. Warmbier".
The two foreign ministers, meanwhile, agreed to build a "future-oriented" bilateral relationship, Kishida said, adding that he explained to Kang the importance of holding a trilateral summit between Japan, South Korea and China.
Moon Jae-in pushed off any talk of a pre-emptive strike against North Korea.
Warmbier's death came just days after he was released by the North Korean government and returned to the United States suffering from what US doctors described as extensive brain damage.
"I believe that my position is not at odds with the policy of the United States or that of President Trump".
Spicer said the USA is continuing to work with China to apply pressure on North Korea and said the U.S. has seen "positive movement" with China.
Earlier this month, Kang, the first female foreign minister in South Korea, said in a parliamentary confirmation hearing that she will seek talks with Japan to reevaluate the controversial agreement.
Asked how the Warmbier case would affect Mr Moon's efforts to engage North Korea as he has said he wants to, the president added: "I believe we must now have the perception that North Korea is an irrational regime".
"We strongly condemn the North's continued attempts at penetrating the South with drones and once again, demand all acts of provocation are halted", he said during the briefing. And then, as a second phase, try to achieve the complete dismantlement of North Korea's nuclear program.