A United States Navy carrier strike group and India’s military that included participation of India’s Russian-designed fighter planes, conducted a weekend exercise in a show of force possibly against China.

The two-day joint force maritime exercise in the Indian Ocean involved the USS Theodore Roosevelt and its three escort ships, U.S. Navy onboard carrier air wings, the Indian navy’s frigate Shivalik and P-8 surveillance plane.

The exercise also included the Indian air force’s Su-30MKI fighter planes, which are manufactured in India under a license.

The maneuvers included a PASSEX, or passing exercise, involving ships of the two countries.

“In a first, enhancing jointmanship, Indian Air Force fighters were also involved in the exercise, affording the IAF an opportunity to practice air interception and air defense with the U.S. Navy,” an Indian Air Force spokesman said.

The exercise focused on anti-submarine warfare, joint air operations, and command and control integration, a U.S. Navy statement on Monday said.

Participating U.S. Navy ships included the carrier USS Theodore Roosevelt, the Ticonderoga-class guided-missile cruiser USS Bunker Hill and the Arleigh Burke-class guided-missile destroyers USS Russell and USS John Finn.

The exercises came one week after U.S. Secretary of Defense Loyd Austin met with Indian leaders in New Delhi.

A Pentagon statement at the time referred to India, traditionally a non-aligned nation, as “a key pillar in U.S. strategy in the Indo-Pacific region.”