The US is reportedly prepared to launch a preemptive strike against North Korea if officials believe Pyongyang is about to move forward with a nuclear weapons test. Multiple senior US intelligence officials have told NBC News that the US is willing to launch a strike using conventional weapons.

US officials say that North Korea's announcement of a "big, important event" could signal a nuclear weapons test, which could happen as early as this weekend.

The US has two destroyers capable of shooting Tomahawk cruise missiles in the area, NBC News reports. One of the destroyers is about 300 miles from North Korea's nuclear test site.

US heavy bombers have also been positioned in Guam in case an attack becomes necessary, and the USS Carl Vinson aircraft carrier strike group is being diverted to the area, the Pentagon announced.

The strike on North Korea could include missiles and bombs, as well as cyber and special operations on the ground, reports NBC News.

Pentagon denies preemptive strike rumours

According to The Hill, the report by NBC has received backlash from sources reported by other journalists. Jennifer Griffin of Fox News reported that multiple defence officials had called the report "wildly wrong" and "crazy". Griffin added that the Pentagon was pushing back on the report, calling it "extremely dangerous".

Other reporters, including Steve Herman and Anna Fifield, tweeted that their defence sources said a pre-emptive strike is "NOT planned".

In a statement issued Thursday (13 April), North Korea warned it would launch a "merciless retaliatory strike" if the US takes action.

"By relentlessly bringing in a number of strategic nuclear assets to the Korean peninsula, the US is gravely threatening the peace and safety and driving the situation to the brink of a nuclear war," the statement said.

South Korean Foreign Minister Yun Byung-se said US officials have "repeatedly reaffirmed" to Seoul that the US "will closely discuss with South Korea its North Korea-related measures". Byung-se added: "In fact, the US is working to reassure us that it will not [act without consulting South Korea], just in case that we might hold such concerns."

US experts do not believe North Korea have a deliverable long-range nuclear weapon nor an intercontinental missile.