North Korea has labeled U.S. national security adviser John Bolton a “warmonger” for saying that recent missile tests by the nuclear-armed country had violated U.N. sanctions, adding that giving up the test-firings would amount to relinquishing their right to self-defense, state-run media quoted the country’s Foreign Ministry as saying Monday.

A statement issued by the official Korean Central News Agency quoted an unidentified Foreign Ministry official as singling out Bolton, who last week said the recent tests had “no doubt” violated United Nations resolutions. Referring to tests of short-range ballistic missiles on May 4 and May 9 that ended a more than 500-day pause in the tests that began in late 2017, the statement also called the launches a “regular military drill.”

What the U.S. is taking issue with “is not about the range but the prohibition of the launch itself using ballistic technology. This is, after all, tantamount to a demand that the DPRK should give up its self-defensive right,” the officials said, using the acronym for the North’s formal name, the Democratic People’s Republic of Korea.

U.S. President Donald Trump, who has repeatedly touted the halt of North Korean missile tests as one of his top foreign policy achievements, has played down the significance of those tests, calling them “very standard.”

On Sunday, in a tweet sent ahead of a round of golf with Prime Minister Shinzo Abe, Trump referred to the tests by Pyongyang as “small weapons” while also praising North Korean leader Kim Jong Un and taking a shot at former Vice President Joe Biden, the front-runner among a slew of Democratic candidates looking to challenge him in the 2020 presidential election.

“North Korea fired off some small weapons, which disturbed some of my people, and others, but not me,” he wrote, in what was widely seen as a reference to Bolton. “I have confidence that Chairman Kim will keep his promise to me.”

“The moratorium was focused, very focused, on intercontinental missile systems, the ones that threaten the United States,” U.S. Secretary of State Mike Pompeo said during a recent television interview. That raised eyebrows in Japan, where the North’s arsenal of shorter-range missiles poses a serious threat because of the country’s proximity to North Korea.

Monday’s statement was issued on the third day of Trump’s first state visit to Japan, where he held talks with Abe and discussed the North’s nuclear arsenal, among other issues.

In targeting Bolton, it said it would “be fit to call Bolton not a security adviser striving for security but a security-destroying adviser who is wrecking peace and security. It is not at all strange that perverse words always come out from the mouth of a structurally defective guy.”

“Such a human defect deserves an earlier vanishing,” the official added.

The criticism of Bolton was the second time in just over a month that Pyongyang had taken aim at him, after a top North Korean official blasted him as “dim-sighted” late last month.

Those remarks were seen as relatively mild for a figure whom the North has in the past described as “human scum” and a “bloodsucker,” and appeared to highlight Pyongyang’s frustration with deadlocked nuclear negotiations.

North Korea has refrained from directly criticizing Trump as it seeks to keep deadlocked denuclearization talks alive.

Kim and Trump have held two summits, the first in Singapore last June and the second in Hanoi in February. The talks have been stalled since the Hanoi summit collapsed without a deal due to major differences over the scope of North Korea’s denuclearization and potential sanctions relief by the U.S.

On Friday, the North warned that the nuclear talks “will never be resumed” unless Washington halts what Pyongyang said were “hostile acts” and demands of “unilateral disarmament,” warning of a “fiercer” response if this continues.