SEOUL -- The United States has made "intentional nuclear war provocations" due to "internal troubles and external woes" as its nuclear-capable B-52H Stratofortress bomber made a first-ever landing in the Republic of Korea (ROK), and indicated a possible preemptive nuclear strike on the Democratic People's Republic of Korea (DPRK), the official Korean Central News Agency (KCNA) said in a commentary on Friday.

The armed forces of the DPRK have been closely monitoring the US introduction of its nuclear strategic assets, in the form of nuclear submarines, nuclear-powered aircraft carriers and strategic bombers, into the Korean Peninsula, and viewed such deployments as grave military moves for a "preemptive nuclear attack aimed at physical removal of the DPRK," the commentary stressed.

The KCNA article also warned that a preemptive strike is no longer an exclusive right of the United States.

It reminded the United States that the DPRK's nuclear force policy, a stated doctrine on using nuclear weapons now enshrined in its constitution, has allowed the country to take necessary actions in case it is under a nuclear attack or it is determined the country is facing an imminent nuclear attack.

The US B-52H bomber landed at a ROK air base in Cheongju, some 110 km south of Seoul, on Tuesday, after it showed up at the Seoul International Aerospace and Defense Exhibition with a fly-over performance, according to the ROK's Yonhap News Agency.