The U.S. military appears to be strengthening its surveillance activities around the Korean Peninsula following North Korea’s recent launches of short-range missiles. 

According to private aviation tracker Aircraft Spots, the U.S. Air Force deployed a reconnaissance aircraft, the RC-135W, over Seoul and Gyeonggi Province on Tuesday, following two other deployments on Monday and last Wednesday. 

The aircraft can detect a forthcoming missile launch by gathering telemetry and other electronic intelligence data and can also track a missile’s trajectory. 

Also observed three times last month over the Seoul metropolitan area, the deployment of the RC-135W may be a part of usual operations by the U.S. military, but some military experts speculate its activity is being augmented amid suspicions Pyongyang may launch more missiles in the future.  

It's known that South Korea and the U.S maintain an enhanced monitoring system on North Korea after detecting the movement of a transporter erector launcher in the North following the two missile launches.