The ghosts of Japan's wartime past will set the tone for the remainder of Shinzo Abe's weeklong visit to the US as he prepares on Wednesday to become the first Japanese prime minister to address a joint session of Congress .

Any references Abe makes to the second world war will be the best indication yet of how he intends to word a key statement he is due to give this summer to mark the 70th anniversary of the end of the Pacific war, amid present-day tensions with China and South Korea.

The first major announcement of his US visit went without a hitch on Monday when the allies unveiled significant changes to their joint defence guidelines. In return for a strong US commitment to Japan's security, including taking Tokyo's side in any conflict with China over the Senkaku/Diaoyu islands, Japan has become a more willing player in its bilateral security arrangements with the US.