‘Nuke sniffer’ and other U.S. spy planes monitoring heightened North Korea threat: Report

A flurry of U.S. Air Force spy and special operations aircraft activity has been reported over the Korean peninsula in recent days, coinciding with heightened concern that North Korea may be readying a major ballistic missile test or other provocation, including a possible nuclear detonation test.

The reporting by CivMilAir and others who claim to track military and civilian flights on social media, comes roughly three weeks after North Korean leader Kim Jong-un announced the end of a self-imposed moratorium on nuclear and intercontinental ballistic missile (ICBM) testing — a moratorium Pyongyang had been adhering to for nearly the past two years.

Concerns over Mr. Kim’s announcement during a New Year’s address were elevated Tuesday, when another key North Korean official reiterated Pyongyang’s months-old threats to pursue a “new path” in the stalled diplomacy with South Korea and Washington.

Ju Yong-chol, a North Korean representative to the United Nations, told a disarmament conference in Geneva on Tuesday — a week after the Trump administration announced fresh sanctions on Pyongyang — that the Kim regime “will steadily develop strategic weapons” until “the U.S. abandons its hostile policy,” according to Agence France-Presse.

Reuters separately cited Mr. Ju as saying Pyongyang has “no reason to be unilaterally bound any longer by the commitment that the other party fails to honor.”

While the Kim regime has carried out waves of short-range missile tests over the past year, it was seen to have embraced a moratorium on more provocative ICBM and nuclear tests as a show of faith in possible nuclear negotiations following the historic 2018 Singapore summit between Mr. Kim and President Trump.

With those negotiations having broken down over the past year, the regime has ramped up its rhetoric, triggering fears that a resumption of long-range tests may be imminent.

The reports of U.S. spy plane activity over the Korean peninsula could not be immediately verified, but may be an indication that American forces at Osan Air Base in South Korea are on elevated alert for possible provocations by the North.

A Twitter account operated by CivMilAir claimed Tuesday that a U.S. Air Force C-146A Wolfhound tactical transport plane had taken off from Osan and headed north toward Mongolia. South Korea’s Chosun Ilbo newspaper, which cited the CivMilAir claim, reported that C-146A’s are known to be used to transport plainclothes U.S. special forces, but are rarely spotted over the Korean Peninsula.

The aircraft’s flight path was not clear, although CivMilAir tweeted there is “no way” it would have entered North Korean airspace.

Chosun Ilbo, meanwhile, cited separate information circulated by flight tracker Aircraft Spots, which claimed to indicate a U.S. Air Force RC-135W Rivet Joint electronic reconnaissance aircraft had flown over South Korea on Tuesday. The newspaper also said a U.S. Navy EP-3E electronic warfare and reconnaissance aircraft had flown over the South a day earlier.

Chosun additionally reported that a U.S. Air Force WC-135W Constant Phoenix special-purpose aircraft — a plane based out of Japan and known in some circles as the “nuke sniffer” — had also recently buzzed skies over waters between Japan and the Korean peninsula.