US President Donald Trump has praised Chinese efforts to rein in "the menace of North Korea", after North Korean state media warned the US of a "super-mighty pre-emptive strike".
Trump told a news conference on Thursday "some very unusual moves have been made over the last two or three hours" and that he was confident Chinese President Xi Jinping would "try very hard" to pressure Beijing's ally and neighbour North Korea over its nuclear and missile programs.
While Trump gave no indication of what the moves might be, US officials told Reuters that the US was aware of a higher-than-usual level of activity by Chinese bombers, signalling a possible heightened state of readiness. The officials played down concerns and left open a range of possible reasons.
Those possibilities included defensive exercises or Chinese concerns over North Korea. None of the officials, who spoke on condition of anonymity, suggested alarm or signalled that they knew the precise reason for such Chinese activity.
US officials have been saying for weeks that North Korea could soon stage another nuclear bomb test, something both the US and China have both warned against.
Trump has taken a hard line with North Korean leader Kim Jong Un, who has proceeded with nuclear and missile programs in defiance of UN Security Council sanctions.
