Japan and Southeast Asian countries have pledged to boost economic and security ties, a day after they agreed on the importance ofensuring freedom of the skies after China declared a controversial air defence zone. The leaders discussed increasing exchanges of top diplomats and defence officials and closer coast guard co-operation, finalising a three-day special summit between Japan and the Association of Southeast Asian Nations (Asean), officials said. In bilateral talks yesterday, Japan and Myanmar also agreed on an investment accord to accelerate Japanese investment in the former junta-ruled country, while Tokyo and Laos agreed to kick-start talks on a civil aviation agreement, officials said. The deal with Myanmar would give Japanese companies so-called national treatment, or rights that local businesses receive in Myanmar when making investment decisions. With Vietnam Prime Minister Nguyen Tan Dung, Abe discussed strengthening co-operation between the coast guards of the two countries which both face territorial disputes with Beijing in the South China Sea or in the East China Sea. In bilateral talks with Vietnam, Laos and Myanmar, Abe took up the issue of China's air defence zone, Jiji Press reported.