The US military has allowed media outlets rare first-hand look at its joint maritime exercise with Japan and South Korea in the East China Sea.

The US Navy, the Japan Maritime Self-Defense Force and the South Korean Navy held drills in waters north of the main island of Japan's Okinawa Prefecture on Thursday and Friday. A total of six vessels from the three countries took part, including the US nuclear-powered aircraft carrier Theodore Roosevelt.

On Thursday, the US military showed jets taking off from the carrier's flight deck to American, Japanese and South Korean media.

The joint drills included confirming procedures to share data to detect submarines and use in search and rescue operations.

Rear Admiral Christopher Alexander, the commander of Carrier Strike Group Nine, told reporters that the significance of this exercise is for three like-minded countries that believe in peace, security and stability in the western Pacific to be better prepared "to respond to any crisis or contingency in the region."

Japan's MSDF said it is uncommon for the media to be allowed to see a joint maritime exercise by the three countries and it's the first time they could do so in at least five years.

Letting the media cover the drills apparently aims to demonstrate cooperation between Japan, the US and South Korea. The move comes amid North Korea's repeated ballistic missile launches and China's increasing maritime activities in the region.