This live blog is now closed. Sign up for the Breaking News US email Donald Trump will drive through a Chinese capital that is smoggier than it was on his last visit in 2017 , when the authorities launched emergency measures to clear the skies of pollution days before his first state visit to Beijing. Factories were ordered to halt production and heavily polluting cars were banned from the roads in the days ahead of the US president’s trip nearly a decade ago, an era in which China had declared war on air pollution and made special efforts to clear the skies ahead of important political events such as visiting dignitaries and the Beijing Olympics.