joint naval exercise

• The Philippines, the US, Japan and Australia will strengthen military ties to counter China's growing influence in the Asia-Pacific region.

• On April 7, the exercise will take place in the South China Sea, which is almost entirely claimed by China. The Philippines, Japan and Taiwan also claim the waters.

• Last week, Australian warship HMAS Warramunga arrived in the Philippine island province of Palawan to strengthen military ties with partner countries.