Donald Trump says Rex Tillerson is 'wasting his time' with North Korea talks
President Donald Trump said his chief diplomat is "wasting his time" trying to negotiate with North Korea about its nuclear and missile programmes.
Mr Trump tweeted the advice to US Secretary of State Rex Tillerson: "Save your energy, Rex, we'll do what has to be done!"
The president did not elaborate, but he told the United Nations last month that if the US is "forced to defend itself or its allies, we will have no choice but to totally destroy North Korea".
Mr Tillerson, while in China, said on Saturday the US is maintaining direct channels of communications with North Korea and probing the North's willingness to talk.
Mr Trump said he has told Mr Tillerson that "he's wasting his time trying to negotiate with Little Rocket Man".
That was a reference to leader Kim Jong Un.