The U.S. military continues to step up surveillance of the Korean Peninsula as a year-end deadline imposed by North Korea for Washington to demonstrate greater flexibility in denuclearization talks fast approaches.

According to private aviation tracker Aircraft Spots on Thursday, the U.S. flew an E-8C reconnaissance aircraft eight-point-eight kilometers over the Korean Peninsula the same day.

The E-8C is known to be capable of monitoring North Korean ground forces and missile bases and was also detected over the peninsula on November 27 and December third. 

Washington has deployed several types of surveillance planes over the peninsula following recent North Korean provocations, including what the regime called a “very important test” at its Tongchang-ri satellite launch site last week. 

An RQ-4 Global Hawk, a high-altitude unmanned surveillance aircraft, also flew over the peninsula on Wednesday.

The same day, an RC-135W recon craft was detected in airspace above the peninsula after being detected earlier on Monday.