Top South Korean, U.S. and Japanese military officers urged North Korea to cease all unlawful activities that threaten regional security, as the three nations flew advanced warplanes for a joint exercise in a show of force against the North.

South Korea, Japan and the United States conducted a joint air drill on Friday involving a U.S. B-52 strategic bomber and fighter jets of the two U.S. allies over international waters, the South's defence ministry said.

Japan and South Korea have until Aug. 1 to agree new trade terms with the U.S., or face 25% “reciprocal” tariffs. The two Asian countries share vulnerabilities that put them in President Trump’s crosshairs,