The United States is monitoring Chinese air activity from E-3 Sentry aircraft based at Kadena air base on Okinawa in response to increasing incidents of Chinese combat and surveillance aircraft shadowing U.S. P-3C and C-130 flights near the Ryukyu islands, according to Japanese and Korean media reports. Chinese pilots are more actively shadowing U.S. military aircraft flying through the airspace between China and Japan. Chinese aircraft have also reportedly violated Japanese airspace near the disputed Senkaku/Diaoyu islands several times since mid-December, prompting Japan to send its aircraft, including F-15Js, to monitor Chinese actions. The use of E-3s would bolster U.S. coordination and provide advance warning of possible encounters with Chinese aircraft, but its purpose may also be to offset some of Japan's weaknesses in the area.