(In this April 19 story, corrects to Australia, Japan second attendance in exercises.))

MANILA (Reuters) - Australian and Japanese troops are joining for the second time annual U.S.-Philippine military exercises involving thousands of troops, as the two-week drills move toward becoming multilateral war games.

The Philippines and the United States have for more than 30 editions been holding bilateral “Balikatan” (shoulder-to-shoulder) drills to test the readiness of their militaries to respond to threats that include natural disasters and militant extremist attacks.

The United States embassy in Manila said in a statement on Thursday that Australia and Japan, two U.S. allies countries with strategic partnerships with the Philippines, would again be included in the exercises at multiple locations on the main island of Luzon, starting on May 7.

Britain has also been invited to observe training for the mitigation of post-disaster suffering.

They will focus on mutual defense, counter-terrorism, humanitarian assistance and disaster relief that can also “provide assistance in the event of crises that endanger public health and safety”.

Soldiers from United States, Australia, Japan and the Philippines have already been renovating schools in four provinces north of Manila as well as providing medical and dental services in poor rural areas, the embassy said.

Philippine military spokeswoman Liezl Vidallon said the four countries would exchange and share information and conduct live- fire training.

The exercises were scaled back last year in response to President Rodrigo Duterte’s disdain for the U.S.-Philippine defense alliance.

He has made no secret of his grudge against the United States and believes a U.S. military presence of any kind in the Philippines puts his country at risk of being dragged into conflict, especially with China, as it beefs-up its maritime defenses.

The volatile leader has showered praise upon Russia and China and invited their warships to come to the Philippines for exercises too.