A South Korean military source told the national outlet Yonhap that his government is ready to reduce Pyongyang “to ashes” after the latest North Korean nuclear test, with “every Pyongyang district… completely destroyed.”

While not an official statement from Seoul, these are the sternest words to come out of South Korea’s government against the belligerent north in recent memory and a sign that South Korea is losing patience with Pyongyang’s repeated threats to attack its neighbor with nuclear weapons.

The military source told Yonhap that a plan is in place to destroy Pyongyang if necessary. “Every Pyongyang district, particularly where the North Korean leadership is possibly hidden, will be completely destroyed by ballistic missiles and high-explosive shells as soon as the North shows any signs of using a nuclear weapon,” the source said. “In other words, the North’s capital city will be reduced to ashes and removed from the map.”

While the South Korean Defense Ministry did not use such language, it did respond to this weekend’s nuclear test with its own official warning that Pyongyang should refrain from threatening it neighbors. Ministry spokesman Jeong Joon-hee called the nuclear test “really deplorable” and urged officials working under dictator Kim Jong-un to cease nuclear development. South Korea also announced the existence of a plan called “Korea Massive Punishment & Retaliation” (KMPR) last week, a comprehensive approach to destroying North Korea should they use nuclear weapons against the south.

South Korea has increasingly used stern language to condemn North Korea. In March, President Park Geun-hye delivered her most strident statement yet, calling for the world to unite to “end the tyranny that has deprived North Koreans of their freedom and human rights.” “I once again strongly urge North Korea to throw away the delusion that the nuclear programs guarantee the regime safety and to walk down the path of genuine change as soon as possible,” she concluded then. North Korea has clearly not abandoned those intentions.

North Korea, in turn, has used belligerent and, at times, vulgar language to refer to the South Korean president. In a three-part series published in 2014 called “We Accuse Park the Bitch,” North Korea’s Rodong Sinmun described the president as, among other epithets, a “bitch,” “cold-blooded animal,” “pumpkin,” and “old cat groaning in her sickbed.”

This weekend, the state-run Korean Central News Agency (KCNA) once again “warned the traitor, hideous confrontation manic [sic] and the nation’s biggest trouble-maker” Park that North Korea plans to attack the south.” KCNA also accused South Korea of “recklessly talking nonsense like psychopaths, utterly fear-stricken by the daily-growing might of the DPRK.”

The communist North Korean government confirmed reports that a nuclear blast had occurred in the country over the weekend, though the tone of North Korean media has been slightly more reserved than in the aftermath of the nation’s fourth nuclear test in January. “Scientists and technicians of the DPRK carried out a nuclear explosion test for the judgment of the power of a nuclear warhead newly studied and manufactured by them at the northern nuclear test ground under the plan of the Workers’ Party of Korea (WPK) for building strategic nuclear force,” the state-run newspaper Rodong Sinmun reported, adding, “The nuclear test finally examined and confirmed the structure and specific features of movement of nuclear warhead that has been standardized to be able to be mounted on strategic ballistic rockets.”

A nuclear bomb that can be mounted on ballistic missiles would pose a threat to South Korea, Japan, China, and nations with vested territorial interests near the Korean peninsula. The South Korean government believes that another nuclear test could occur at any time.

“North Korea appears to be fully ready to carry out a nuclear test at its Punggye-ri test site on short notice. We are closely watching for any moves indicating another test,” an unnamed South Korean official told Yonhap Monday.