The United States flew a naval surveillance aircraft over the Korean Peninsula, an aviation tracker said Wednesday, the latest in a series of flights of its aircraft to monitor North Korea amid concern over the North's military moves.

The US navy's P-3C maritime surveillance plane was spotted flying over the Korean Peninsula at 22,000 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.

According to the aviation tracker on Tuesday, the US sent its E-8C spy plane, or JSTARS, as well as RC-135U Combat Sent aircraft, just days before conducting other operations over the peninsula.

On Monday, the RC-135W Ribet Joint was also spotted over South Korea and the U-2S plane over the weekend. The EP-3E and RC-135V reconnaissance jets were detected here last week, the aviation tracker said.

The deployment of several types of surveillance planes over the peninsula came at a time when North Korea has ratcheted up tensions through military moves as the year-end deadline that Pyongyang set for Washington to come up with new proposals in nuclear negotiations draws near.

On Thursday, the North test-fired a super-large multiple rocket launcher as the 13th round of major weapons tests so far this year.

Last month, the North carried out coastal artillery firing drills under the guidance of leader Kim Jong-un on the Yellow Sea border islet of Changrin in violation of the inter-Korean military agreement signed in September last year. 

The US might be intentionally allowing its military aircraft to be spotted so as to send a warning message to North Korea, while carrying out its operations in the region "at a normal level," according to experts and military sources.

As stepped-up pressure on Pyongyang, US President Donald Trump on Tuesday hinted at the possibility of military action against North Korea if necessary, while emphasizing his "good" relationship with leader Kim. (Yonhap)