US Secretary of State Hillary Clinton today said President Barack Obama will invite Southeast Asian leaders to a summit in Washington later this year. Mrs. Clinton told the 27-member ASEAN Regional Forum security dialogue in Hanoi that the key element of US strategy is to strengthen regional and global institutions. She termed ASEAN and the ASEAN Regional Forum as important pieces of a strong, effective architecture for security and prosperity in Asia. Mrs. Clinton said the US seeks to support these institutions and work more closely with them.