Okinawa residents protest over new US military base
27 April 2015 Last updated at 17:06 BST
Japan's Prime Minister Shinzo Abe is visiting the United States and will travel to Washington where he will become the first Japanese leader ever to address a joint session of Congress.
The visit is designed to show the strength of the countries' alliance and to improve co-ordination on trade and defence.
Mr Abe will tell President Obama that construction has begun on a huge new US marine base on the southern island of Okinawa despite protests from local residents.
Our Tokyo Correspondent Rupert Wingfield-Hayes has been to Okinawa to find out more.