The United States and China have significantly increased the volume of military exercises across Asia amid roiling regional tensions in recent years, though Beijing's drills still lag in scale and complexity, a new study has found.

In a survey of military exercises in Asia between 2003 and 2022, the London-based International Institute of Strategic Studies said drills are expanding at an increasing rate, driven in part by U.S. and Chinese efforts to test capabilities and boost strategic diplomacy.

The IISS study "Scripted Order," released on Friday, charted some 1,113 U.S. exercises involving Asian countries, compared with 130 run by China.