`North Korea now a nuclear threat to be reckoned with, Washington can expect more nuclear tests and missile launches`

Pyongyang: The top North Korean official for US relations today said that his country is now a nuclear threat to be reckoned with, and Washington can expect more nuclear tests and missile launches like the ones earlier this week as long as it attempts to force his government's collapse through a policy of pressure and punishment.

"It's the United States that caused this issue," Han Song Ryol, director-general of the department of US affairs at North Korea's Foreign Ministry, told AP in his first interview with an American news organisation since assuming the post three years ago.

"They have to stop their military threats, sanctions and economic pressure. Without doing so, it's like they are telling us to reconcile while they are putting a gun to our forehead."

Han defended the North's test-launching on Wednesday of two medium-range ballistic missiles. Foreign military experts believe that, once perfected, such missiles could deliver nuclear warheads to US bases in Japan and possibly to major US military installations as far away as the Pacific island of Guam, where long-range US Air Force bombers are deployed.

The tests indicated technological advances in the North's missile capabilities. They were quickly condemned by Washington, Tokyo and Seoul as a "provocation" and a violation of United Nations resolutions.

State Department spokesman John Kirby said US policy calling for the denuclearisation of the Korean peninsula hasn't changed.

"The capabilities that the DPRK continues to pursue are doing nothing obviously to get us to that goal," he said. "We urge the North to take the necessary steps to prove that they're willing to return to the six-party talk process, so that we can get to that goal."

Han dismissed the criticism, saying North Korea has no choice but to build up its military deterrent as long as the world's largest superpower, and the country that first developed nuclear weapons, remains an enemy.

He noted that the US recently deployed nuclear-powered submarines and strategic bombers capable of dropping nuclear weapons on North Korea to the region, and earlier this year conducted training for precision airstrikes on North Korea's leadership, along with simulations of an advance into the capital, Pyongyang, with the South Korean military during joint annual exercises.

"This launch was a significant and novel step that my country must take to produce a powerful nuclear deterrent," Han said. "The real provocation is coming from the United States. ... How can my country stand by and do nothing?"

Han said North Korea has never recognised a longstanding United Nations Security Council ban on its testing of nuclear weapons or long-range missiles, though the world body has ratified the resolutions and imposed heavy sanctions on North Korea for continuing them, including a round of new sanctions imposed after its latest nuclear test in January. North Korea says that test was its first of an H-bomb.