US President Donald Trump and other world leaders are to address the annual Asia-Pacific Economic Co-operation (Apec) summit in Vietnam, with trade and growth high on the agenda. <br/><br/>Mr Trump has vowed to correct a huge trade imbalance with China and Japan. China yesterday said it will ould lower market entry barriers to some sectors, during Mr Trump's visit to Beijing.<br/><br/>Talks between Mr Trump and Russian President Vladimir Putin are yet to be confirmed at the summit in Danang. Apec brings together 21 economies – the equivalent of about 60% of the world's GDP.