Pyongyang on Monday again lashed out at Seoul for its recent test of a new ballistic missile capable of hitting anywhere in North Korea, threatening retaliation against what it said was a “grave provocation.”

South Korea’s Defense Ministry said last week that the March 23 test-firing was successful and the missile has a range of 500 kilometers and a payload of 1 ton.

“If a U.S. missile or the South Korean puppet forces’ missile falls on any part of the DPRK (North Korea), we will pound all the strongholds of the enemy with a merciless shower of missiles to reduce them to ashes,” the North’s National Academy of Defense Sciences said in a statement carried by the official Korean Central News Agency.

The ministry’s announcement came days after the U.N. Security Council condemned the North’s ballistic missile tests late last month, prompting the communist regime to threaten a “new form of nuclear test” to further its nuclear deterrence.

Pyongyang has since churned out criticism, accusing Seoul and Washington of operating a “double standard” by denying its right to self-defense while beefing up their own military capabilities.

South Korea has unveiled plans to deploy the 500-km range missile next year and develop an 800-km range missile with a payload of 500 kg under a 2012 agreement with the U.S.

The North has deployed ballistic and other missiles with various ranges capable of reaching South Korea, Japan and U.S. military bases in the Pacific, while developing intercontinental ballistic missiles and technology to miniaturize nuclear warheads to mount on them.

“The South is in no position to criticize our exercise of self-defense such as our legitimate test of rockets,” the spokesperson of the North’s strategic missile force was quoted Saturday as saying by the KCNA.

Tension has been increasing on the peninsula amid a series of rocket launches and military exercises on both sides of the border, Pyongyang’s threats of a fourth nuclear test, and the recent discovery of North Korean spy drones in the South.

The North has also reportedly notified Japan of its plan for further maritime artillery exercises and missile tests in the East Sea until mid-April.

In Washington, the chief nuclear negotiator of South Korea, the U.S. and Japan are scheduled to meet to discuss ways to ramp up the three countries’ trilateral coordination and revive a six-nation forum aimed at denuclearizing the unruly state.

The Rodong Sinmun, a Workers’ Party mouthpiece, on Monday reasserted the country’s need for a nuclear deterrent, saying that without it the North would suffer from “unbearable humiliation and tragedy.”

“The unilateral demand on us to give up nuclear weapons will forever remain a daydream. We will only relentlessly continue to consolidate, strengthen and develop our nuclear forces,” it said.

The article added to growing concerns over a fourth underground detonation. Pyongyang’s deputy U.N. representative Ri Tong-il repeated Friday that his country “made it very clear we will carry out a new form of nuclear test,” adding “I recommend you to wait and see what it is.”

By Shin Hyon-hee (heeshin@heraldcorp.com)