The Philippines and the United States have begun joint annual military exercises on a much smaller scale than usual.

The drills, dubbed Balikatan (Shoulder-to-Shoulder), began on Monday. They are the first under President Rodrigo Duterte.

This year’s exercises will be based on a scenario of troops responding to a major storm hitting the eastern Philippines, then cutting across the heavily-populated areas of the country, including the capital, Manila.

Officials say 5,400 personnel, including 2,600 Americans and 2,800 Filipinos, are participating in the exercises this year. That is down from 12,000 in 2015.

The US co-director of this year’s drills, General Lawrence Nicholson, said the US military hoped that the exercises would grow again in future editions.

“If you look back on 33 years of Balikatan, they are all different. There are any number of ways it can change. It can be bigger, it can be smaller. We hope it gets bigger,” Nicholson told reporters.

US troops march during the opening of the annual Philippines-US military exercises at Camp Aguinaldo, Quezon City, Manila, the Philippines, May 8, 2017. (Photo by AFP)

The two countries have long been conducting the yearly drills. The Philippines, one of the oldest US allies in Asia, also hosted permanent US military bases until 1992.

Ties between the two, however, started weakening since last year, when Duterte said he wanted US troops out of his country in the next two years. He repeatedly clashed with Washington over his anti-drug campaign, which was criticized by the US and rights groups.

The anti-drug campaign has so far killed thousands of people in the South Asian country.

Despite the downgrade of military ties initiated by Manila, Washington has pledged to remain “committed to our pursuit of shared objectives” in keeping with the “seven-decade alliance between our two countries.”