(US Air Force)
It did not specify the exact time of the operation.

The flight came amid lingering concerns that the North could conduct additional missile launches amid stalled denuclearization talks with the United States. So far this year, the communist country has conducted 12 rounds of major weapons tests involving new types of short-range ballistic missiles and a submarine-launched ballistic missile.

Further heightening tensions, the North on Saturday carried out firing drills involving coastal guns on its border islet of Changrin in the Yellow Sea under the guidance of leader Kim Jong-un. Calling the drills a violation of the inter-Korean military pact signed last year, the Seoul government protested strongly and urged Pyongyang to stop such acts.

Stepping up its surveillance of North Korea, the US has flown the reconnaissance plane that conducts signals intelligence over Seoul and its surrounding areas more often recently than before. (Yonhap)

A US reconnaissance plane flew over Seoul and surrounding regions, an aviation tracker said Wednesday, on an apparent mission to collect intelligence regarding North Korea. The plane, believed to be an RC-135V, was detected in the skies above South Korea's capital city and Gyeonggi Province "on task over the Korean Peninsula," Aircraft Spots posted on Twitter.