President Barack Obama will become the first U.S. president to visit Japan's city of Hiroshima. It is a huge event for the USA and Japan. Hiroshima is the first city to suffer from atomic weapons. The bomb that U.S. forces dropped on the city in 1945 killed around 140,000 in that year. Some historians say it helped end World War II. Others say it should never have happened. President Obama said his visit is to focus on the future. Mr Obama will not apologise for the bombing. An advisor said Obama, "will offer a forward-looking vision" that focuses on the shared future of the USA and Japan.

Barack Obama has wanted to visit Hiroshima for many years. People in Japan and the USA are now talking about the bombs that killed so many people. Mr Obama said his visit would be a time to think about the horror of war, and to remember the loss of life. He hopes his time in Hiroshima will remind people that war causes unnecessary death and that nuclear weapons should never be used. He said he wants people to know that innocent people caught in war suffer a lot. He added: "And that's not just the thing of the past. That is happening today in many parts of the world."