North Korean Foreign Minister Ri Su-yong has said his country will suspend its nuclear tests if the US stops its annual military exercises with South Korea.

Ri Su-yong also told the Associated Press that his country would not be cowed by international sanctions.

A US official has defended the drills as a sign of commitment to South Korea.

Meanwhile, Pyongyang said April 23 submarine-launched ballistic missile test was a “great success”.

“It fully confirmed and reinforced the reliability of the Korean-style underwater launching system and perfectly met all technical requirements for carrying out… underwater attack operation,” the North Korean news agency KCNA said.

The report added that the test gave North Korea “one more means for powerful nuclear attack”.

North Korea is banned from nuclear tests and activities that use ballistic missile technology under UN sanctions dating back to 2006.

Earlier, Ri Su-yong defended North Korea’s right to have a nuclear deterrent and said the US drove North Korea to develop such weapons as an act of self-defense.

The minister said that the suspension of the military drills could open the door to talks and reduced tensions.

“If we continue on this path of confrontation, this will lead to very catastrophic results, not only for the two countries but for the whole entire world as well,” he told AP.

“Stop the nuclear war exercises in the Korean Peninsula, then we should also cease our nuclear tests.”

It was a rare interview by a top North Korean official with a foreign media outlet. The conversation took place in North Korea’s diplomatic mission at the UN, AP said.

An unnamed US official quoted by AP defended the drills in South Korea as demonstrating Washington’s commitment to its alliance with Seoul.

The US has insisted North Korea give up its nuclear weapons program first before any negotiations and has ignored similar proposals in the past, according to the agency.

Ri Su-yong also said sanctions would not sway his country: “If they believe they can actually frustrate us with sanctions, they are totally mistaken.

“The more pressure you put on to something, the more emotionally you react to stand up against it. And this is important for the American policymakers to be aware of.”

The interview came hours after North Korea said it launched a ballistic missile from a submarine, a type of missile hard to detect.