Japan has begun construction work on a military radar station near a string of islands that is at the centre of a territorial dispute with China. The new base – on Yonaguni island – is located just 150km (90 miles) from the Japanese-held Senkaku island group, claimed by China as the Diaoyu islands. When they meet on Thursday, Prime Minister Shinzo Abe and U.S. President Barack Obama are expected to underline the Japanese-US military alliance and stress to China that they will not tolerate any attempt to alter the status quo by force or coercion. The islands have been a scene of maritime stand-offs between Japanese and Chinese vessels and late last year China declared an Air Defence Identification Zone there. In the coming year, the United States plans to put more of a strategic focus on the Asia-Pacific.