Japanese Prime Minister Shinzo Abe hailed an "historic" success as he and US President Barack Obama signed an agreement on security issues and made progress in bilateral trade talks.
The two countries issued a joint statement saying they oppose attempts to assert territorial or maritime claims by coercion and specifying that their bilateral security treaty covers Japanese islands claimed by China.
They failed to reach a bilateral trade deal that is key to both leaders' agendas. But Abe said they achieved a "key milestone" by making progress on the talks, which they said will inject "fresh momentum" into attempts to reach a 12-nation Trans-Pacific Partnership pact.
More top news
Medical staff who helped during the Westminster terror attack have received a royal thanks for their life-saving efforts.
Colin Gregg, the son of the founder of the Greggs bakers chain, has been jailed at Newcastle Crown Court for 13 and a half years.
Khalid Masood was killed by a single gunshot to his chest, after the terror attack which claimed the lives of four people, an inquest heard.