The governments of Japan and Vietnam are making arrangements for Nguyen Phu Trong, general secretary of Vietnam's ruling Communist Party, to make his first visit to Japan, sources in both countries said Tuesday.

The visit could take place as early as September, sources connected with Vietnam's Communist Party indicated. Trong outranks President Truong Tan Sang and Prime Minister Nguyen Tan Dung in the country's leadership hierarchy.

Trong visited the United States earlier this month, becoming the party's first chief to do so since the end of the Vietnam War. He met with U.S. President Barack Obama and they shared concerns about Chinese activities to press sovereignty claims in the South China Sea. Both countries view China's actions in that area as contravening international law.