US President Barack Obama arrives in Japan Wednesday to attend the final G7 summit of his presidency. He will meet with Prime Minister Shinzo Abe on the sidelines and later visit the western city of Hiroshima.
Here are top issues surrounding his trip to Japan.
Hiroshima and the atomic bomb
On Friday, Obama will become the first sitting US president to visit Hiroshima since it was destroyed by an atomic bomb in August 1945, in the last days of World War II.
The White House has said his visit will "highlight his continued commitment to pursuing the peace and security of a world without nuclear weapons," but made clear that he will not offer an apology for the bombing.
Obama will travel to Hiroshima “to honour all those who were lost during the war," said Daniel Kritenbrink, a top Obama advisor on Asia.
US military on Okinawa
The issue of the US military presence on the island of Okinawa is expected to be prominent among the topics discussed by Obama and Abe following the recent arrest of a former US Marine in connection with the death of a local woman.
The death is expected to further strengthen political and environmental opposition to the construction of a new US military base on the northern part of the island. The new base would take over the functions of US Marine Corps Air Station Futenma, which Japan and the US first agreed to close in 1996, but have so far failed to do.
Obama and Abe are likely to discuss territorial disputes in the South and East China Seas, and China’s military buildup and increased assertiveness in the region. Japan wants to increase its role in the South China Sea dispute, although Beijing has urged Tokyo not to become involved.
At a meeting of G7 foreign ministers in April, Japan and the US strongly opposed "provocation" in the seas without explicitly naming China, a move that nevertheless prompted a protest from Beijing.
Once again, the United States and Japan are likely to condemn North Korea over its nuclear and missile programmes. Pyongyang conducted a fourth nuclear test in January and a long-range rocket launch in February, and continues to issue threats of war against its main enemies.
The tests prompted the UN Security Council in March to unanimously pass a resolution significantly tightening sanctions on the reclusive country.