US and South Korean officials have been saying for weeks that the North could soon stage another nuclear test, something the United States, China and others have warned against.
South Korea has put is forces on heightened alert.
China, North Korea’s sole major ally which nevertheless opposes Pyongyang’s weapons programmes and belligerence, has appealed for calm. The United States has called on China to do more to help defuse the tension.
Last Thursday, Trump praised Chinese efforts to rein in ‘the menace of North Korea’, after North Korean state media warned the United States of a ‘super-mighty preemptive strike’.