North Korea flag
North Korea flagiStock

North Korea will continue the "acceleration" of its nuclear and missile programs despite the United States’ threats to impose sanctions on it, a North Korean official told Reuters on Tuesday.

Choe Myong Nam, deputy ambassador at the North Korean mission to the United Nations in Geneva, told the news agency that North Korea has nothing to fear from any U.S. move to broaden sanctions aimed at cutting it off from the global financial system.

The country is developing a "pre-emptive first strike capability" and an inter-continental ballistic missile (ICBM), he added.

Choe was responding to a report on Monday which said that the Trump administration is considering imposing sanctions aimed at cutting North Korea off from the global financial system, part of a multi-pronged approach of increased economic and diplomatic pressure on the isolated country.

"I think this is stemming from the visit by the Secretary of State (Rex Tillerson) to Japan, South Korea and China...We of course are not afraid of any act like that," Choe told Reuters.

"Even prohibition of the international transactions system, the global financial system, this kind of thing is part of their system that will not frighten us or make any difference," he added, calling the existing sanctions on North Korea "heinous and inhumane".

North Korea has been under sanctions for "half a century" but it survives by placing an emphasis on "self-sufficiency", he continued, adding his country wants a forum set up to examine the "legality and legitimacy of the sanctions regime".

Earlier this week, North Korea tested a powerful new rocket engine, a test hailed by leader Kim Jong Un as a "new birth" for the nation's rocket industry.

The test occurred two weeks after Pyongyang fired ballistic missiles into the sea off Japan's northwest coast.

The ballistic missile test was said to have been a training exercise for a strike on American bases in Japan.

Choe declined to give technical details of North Korea's latest rocket engine test on Sunday, calling it only a great historical event that would lead to "fruitful outcomes".

The UN Security Council condemned North Korea following its last ballistic missile test, but those condemnations have done little to deter Pyongyang. UN sanctions have also had little effect.