Should the United States be worried about being obliterated by North Korea?

North Korea's official, state-run news agency, the KCNA, recently outlined plans by the infamous leader of the pariah state, Kim Jong-un, which involved building nuclear weapons that can bring complete and utter destruction to America.

The news agency controlled by the North Korean government reported that the nation's scientists "are in high spirit to detonate H-bombs of hundreds of kilotons and megatons, capable of wiping out the whole territory of the U.S. all at once."

This apocalyptic warning to the U.S. came a few days after North Korea claimed to have successfully conducted a test detonation of a powerful hydrogen bomb.

North Korea even released a supposed footage of its leader watching from afar a submarine-launched ballistic missile which could deliver a nuclear payload.

Experts, however, doubt both the authenticity of this footage and North Korea's general claim that it has tested a hydrogen bomb.

Scientists think the yield of the supposed North Korea H-bomb test – around six kilotons – was very low for a full-fledged thermonuclear device. This kind of devices would normally be 100 times more powerful compared to North Korea's claim.

Notwithstanding the doubts being cast on its claims, North Korea, through KCNA, said the hydrogen bomb test is only part of a "normal course" in which countries have to develop nuclear weapons for external defence.

According to KCNA, North Korea did not intend to "threaten" anyone or to "provoke" someone with its supposed nuclear test. Instead, it would just like to make sure that it is immune from external aggression, particularly from the U.S.

On Monday, the U.S. House of Representatives unanimously passed legislation calling for broader sanctions on North Korea.

South Korea also condemned the alleged nuclear test, with President Park Geun-hye warning of more "provocations" from the North.

"We are cooperating closely with the United States and allies to come up with effective sanctions that will make North Korea feel bone-numbing pain, not only at the Security Council but also bilaterally and multilaterally," she said in a recent speech, as quoted by The Daily Mail.

Despite condemnations and the threat of sanctions, North Korea's Kim seemed unperturbed as he reportedly ordered a further expansion of the size and power of his country's nuclear arsenal.