The United States flew a surveillance plane over the Korean Peninsula, an aviation tracker said Thursday, the latest in a series of near-daily flights to monitor North Korea amid growing concerns Pyongyang could test-fire a long-range missile.

The E-8C aircraft, or JSTARS, was spotted over the Korean Peninsula at 29,000 feet, Aircraft Spots said on its Twitter account without specifying the exact time of the operation. It also did not upload photos showing the flight route.

As a platform for airborne command and control, surveillance and reconnaissance, the E-8C is known to be capable of closely monitoring North Korea's troops and equipment movements, including missiles and artillery guns. It was recently spotted over South Korea, the aviation tracker said on Tuesday. 

Then on Wednesday, the Twitter account said that the US deployed its key spy asset Global Hawk over the peninsula and a strategic B-52 bomber over the sea near Japan.

Such flights came amid heightened tensions in the region after Pyongyang conducted a rocket engine test at its Dongchang-ri satellite launching site on Saturday, sparking speculation that it may be gearing up to resume testing of intercontinental ballistic missiles amid stalled denuclearization talks with the US.

North Korea has threatened to seek "a new way" if the US fails to come up with new proposals by the end of this year to move their dialogue forward.

As the North has taken a series of military moves such as successive firings of short-range ballistic missiles and a submarine-launched ballistic missile, the US has deployed several types of surveillance planes over the peninsula more often than before. Sources and experts see those operations, at least in part, as designed to send warning messages against the bellicose regime. (Yonhap)