Donald Trump’s warning that he could take unilateral action to eliminate North Korea’s nuclear threat has sparked alarm among some analysts in Asia about the implications for South Korea, Japan and China of a military conflict with Pyongyang.

“China has great influence over North Korea. And China will either decide to help us with North Korea, or they won’t,” Mr Trump told the Financial Times in an interview in the Oval Office. “If China is not going to solve North Korea, we will.”

The comments by the US president came weeks after Rex Tillerson, secretary of state, declared during a visit to Asia that the US policy of “strategic patience has ended”. Mr Tillerson said that Washington would not rule out any option in response to provocations by North Korea.