This week it called the South Korean leader, Park Geun-hye, a "dirty prostitute" and a "running dog." It called President Barack Obama, who had been visiting South Korea, Park's "pimp" and "master."
Offensive language is not unprecedented from North Korea, where the use of extreme insults against perceived enemies is standard practice. But the latest invective, laced with misogynic themes, was contained in an official statement from a North Korean government entity that presumably promotes reconciliation.
It also came amid fears that after several months of a relative lull on the divided Korean Peninsula, Pyongyang might raise tensions again by conducting another nuclear test. In the past several days, South Korean officials and U.S. experts have reported heightened activities in an underground nuclear test site in northeastern North Korea.
The North's Committee for the Peaceful Reunification of Korea, which is presumably in charge of relations with South Korea, heaped the insults on Park in a statement issued late Sunday to criticize the summit meeting between Park and Obama in Seoul on Friday.
Park and Obama urged the North to give up its nuclear weapons development, warning that a new nuclear test would only lead to harsher international sanctions. They also pledged to pressure the Pyongyang government over human rights abuses chronicled by a recently published UN investigation.
The summit meeting convinced North Korea that it "must settle its final scores with the U.S. through an all-out nuclear showdown," the North Korean committee said.
It called Park "an immature girl" and her remarks "filthy water," saying that Pyongyang no longer saw any hope of improving ties with Seoul under her leadership.
It also called Park, who is unmarried, America's "comfort woman," a euphemism used to describe Korean and other Asian women enslaved in front-line brothels for Japanese soldiers during World War II.
"It is immorality itself for the North to continue to use such unspeakable foul language," Kim Eui-do, a South Korean government spokesman, said during a news media briefing Monday.
During the Cold War years, the two Koreas traded vile language across their border. The North called the South a "puppet" of the Americans, while the South called the North Korean communists "rabid dogs."
The insulting appeared to ease after the 2000 inter-Korean summit, when both sides agreed to cease cross-border slander. But as relations were aggravated in recent years, the North's verbal attacks have become increasingly extreme, often aimed at Park and her predecessor, Lee Myung-bak, a fellow conservative.
The North has warned that Park would face the same fate as her father, the former South Korean strongman Park Chung-hee, who was assassinated by his spy chief in 1979.
After the Obama-Park summit meeting, where the two reconfirmed their positions on North Korea but offered no new incentive for talks, "the chances of a nuclear or ballistic missile test by the North have increased," said Cheong Seong-chang, a senior fellow at Sejong Institute in South Korea.
Fears that the cycle of provocations by North Korea and punitive sanctions by the UN Security Council was about to repeat itself on the divided Korean Peninsula have recently increased amid signs of preparations for a possible nuclear test in Punggye-ri, the test site in northeastern North Korea.
On Monday, 38 North, a website specializing in North Korea, reported that new commercial satellite imagery from Friday had confirmed a further increase of activity at Punggye-ri, where the North has conducted three nuclear tests, the latest in February last year.
In an analysis published Friday by the Washington-based Institute for Science and International Security, two researchers, David Albright and Serena Kelleher-Vergantini, also reported heightened activity at the test site.
But it remained unclear from the imagery whether any test tunnels had been sealed, a sign that a test may be imminent, 38 North said.