Japanese Prime Minister Shinzo Abe arrived in Vietnam on Wednesday at the start of a regional tour aimed at strengthening economic and security ties, his first overseas trip since winning power.
Abe will spend less than 24 hours in Vietnam before heading to Thailand and Indonesia in an attempt to bolster relations with the vibrant economies of the Association of Southeast Asian Nations bloc.
He is scheduled to meet Prime Minister Nguyen Tan Dung and other top officials in Hanoi later Wednesday.
Last year Japan became the largest single foreign investor in Vietnam, with major investments in banking, export-orientated manufacturing and consumer goods as Japanese companies eye the rapidly-expanding middle class.
Japan is also Vietnam's largest aid donor and political and security ties are growing as Tokyo seeks to shore up regional relationships as a counterweight to an increasingly confident China.
"Currently, the strategic environment in the Asia-Pacific region is going through a dynamic change," Abe, who scored a handsome election win last month after talking tough on a territorial dispute with China, told reporters before departing.
"During this change, having closer relations with ASEAN countries contributes to the region's peace and stability and is in Japan's national interest."
Japan and China are locked in a bitter battle over the sovereignty of the Tokyo-controlled Senkaku islands, which Beijing calls the Diaoyus.
Vietnam and China have competing claims to the Paracel and Spratly Islands, and regularly trade diplomatic barbs over sovereignty and fishing rights in the contested waters around the archipelagos.
China is also involved in an acrimonious territorial dispute with the Philippines over parts of the South China Sea.