US President, Donald Trump has embarked on an 11-day trip to Asia during which he will visit Japan, South Korea, China, Vietnam and the Philippines. It will be the longest tour of Asia by a US president in 25 years. <br/><br/>The trip comes at a time of heightened tensions with North Korea over its nuclear programme and missile tests. Mr Trump is expected to show a united front with South Korea and Japan while pressing China to take a stronger line with Pyongyang. <br/><br/>President Trump flew first to the US state of Hawaii where he visited the USS Arizona Memorial at Pearl Harbor – the scene of the 1941 Japanese attack that drew the US into World War Two. From Hawaii, he will head to Japan and then on to South Korea. <br/><br/>In Vietnam, Mr Trump will attend the Asia-Pacific Economic Co-operation summit in Danang and make a state visit to Hanoi. His final engagement will be a summit of South-East Asian nations in the Philippine capital, Manila.