US President Donald Trump has arrived in Japan at the start of a 12-day trip to Asia with South Korea, China, Vietnam and the Philippines also on his itinerary. <br/><br/>It will be the longest tour of Asia by a US president in 25 years. President Trump arrived at the Yokota US Air Force base west of Tokyo today morning where he addressed the US service personnel. He will later today meet Japanese Prime Minister Shinzo Abe for lunch before the two leaders play a round of golf.<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 and urge China to be firmer with Pyongyang. <br/><br/>The president told reporters on board Air Force One that he expected to meet Russian President Vladimir Putin during his Asian trip.'