The 39th Balikatan Exercise, an annual bilateral drill between the Philippines and United States, opened on Monday at Camp Aguinaldo.

US Embassy Charges d' Affaires ad interim Robert Ewing was the guest of honor, representing US Ambassador to the Philippines Mary Kay Carlson, alongside Armed Forces of the Philippines chief Gen. Romeo Brawner.

Ewing said Balikatan ''embodies the deep spirit of collaboration and partnership that has defined the enduring alliance between the United States and the Philippines for decades.''

Brawner said the Balikatan ''stands as evidence of our continuous effort to enhance the cooperation, dedication and mutual intentions the strengthen the interoperability of our forces.''

With 16,000 service members participating across Luzon in the exercises which will end May 10, Balikatan will focus on the changing security landscape in the region. It is poised to become the most comprehensive exercise in 39 years.

The Philippine Navy, the US Navy, and the French Navy will also conduct a Multilateral Maritime Exercise in the West Philippine Sea.

There will be observers from Brunei Darussalam, Canada, France, Germany, India, Indonesia, Japan, Malaysia, New Zealand, South Korea, Singapore, Thailand, the United Kingdom and Vietnam.

For the first time, troops from the French Navy will also join the drills, along with contingents from the Australian Defence Force.

The field training exercise features four combined joint all-domain operations, which include the following: exercises in protecting key terrain in Luzon and Palawan in support of territorial defense; rapidly moving long range, precision strike capabilities and using them in targeting simulated threats; tracking simulated air threats and targeting them with multiple air and missile defense systems; and integrating multilateral air and land platforms to increase awareness of the maritime security situation, the US Embassy said last week. DMS