Russia has moved heavy military equipment towards its border with North Korea amid mounting fears of a military clash between Pyongyang and the United States over the North’s nuclear program.

A flurry of military activity in Russia's far east came as the UN Security Council strongly condemned North Korea's latest missile test and threatened to impose new sanctions against Pyongyang for its "highly destabilizing behavior."

In a unanimous statement, the council demanded that North Korea "conduct no further nuclear tests" and said Pyongyang's "illegal missile activities" were "greatly increasing tension in the region and beyond."

North Korea carried out a failed missile test on Sunday, a day after displaying missiles at a parade in Pyongyang.

The Rodong Sinmun, the official newspaper of the North's ruling Workers' Party, said in an editorial on Thursday: "In the case of our super-mighty preemptive strike being launched, it will completely and immediately wipe out not only US imperialists' invasion forces in South Korea and its surrounding areas but the US mainland and reduce them to ashes,".

The threat appeared to be a response to comments by Rex Tillerson, the US Secretary of State, who said on Wednesday the US was looking for ways to “bring pressure” on the North Korean regime into giving up its nuclear ambitions.