US DEFENCE Secretary Pete Hegseth declared that the US is "prepared" for war with China in response Beijing's chilling World War Three threat. President Trump's fresh 25 per cent tariffs on imports from Mexico and Canada took effect on Tuesday, along with doubled duties on Chinese goods - sparking devastating trade wars. 7 US Secretary of Defence Pete Hegseth speaks as he meets with Saudi Defense Minister in February Credit: AFP 7 President Donald Trump, left, meets with Chinese President Xi Jinping in 2019 Credit: AP 7 US President Donald Trump addressed a joint session of Congress on Tuesday Credit:...