US Defense Secretary Leon Panetta Friday sought to promote Washington's strategic shift to the Asia-Pacific and a tentative rapprochement with Myanmar as he met counterparts in the region.

"The message I have conveyed on this visit is that the US rebalance to the Asia-Pacific is real, it is sustainable, and it will be ongoing for a long period of time," Panetta said.

The US is deepening its military engagement with allies in the region, he told reporters after talks with counterparts from the Association of Southeast Asian Nations (ASEAN) in Cambodia.

He said the Pentagon would increase the size and number of its defense exercises with its Southeast Asian partners.

Fresh from reelection victory, US President Barack Obama will arrive in the region next week for a historic visit to Myanmar before joining his top diplomat Hillary Clinton in Cambodia for the summit.

Obama will be the first sitting US president ever to go to Myanmar following a series of dramatic political changes in the state, which is emerging from decades of military rule.

The White House said Thursday that Obama would meet Chinese Premier Wen Jiabao and Japanese Prime Minister Yoshihiko Noda next week on the sidelines of the ASEAN summit.