(JTA) — North Korea threatened Israel with “merciless, thousand-fold punishment” and labeled it the only “illegal possessor” of nuclear weapons in the Middle East.

The Foreign Ministry in Pyongyang issued a statement Saturday blasting Israel after its defense minister, Avigdor Liberman, in an interview with the Hebrew-language news website Walla! called North Korean leader Kim Jong-un a “madman” who is in charge of a “crazy and radical group” that is “undermining global stability.”

Liberman said that Pyongyang “seems to have crossed the red line with its recent nuclear tests,” according to Walla!.

Also Saturday, North Korea conducted a failed ballistic rocket test, the second test of a long-range Scud-type missile this month, which also failed. The test came as the United States began joint naval exercises with South Korea just after the U.S. aircraft carrier group led by the USS Carl Vinson entered the Sea of Japan.

North Korea could be ready to conduct its sixth nuclear test, according to reports.

In its statement slamming Israel, North Korea called Israel the “only illegal possessor of nukes in the Middle East, under the patronage of the U.S.”

“The reckless remarks of the Israeli defense minister are sordid and wicked behavior and a grave challenge to the DPRK (the Democratic People’s Republic of Korea, or North Korea),” the Foreign Ministry’s statement read.

“This is the cynical ploy to escape the world denunciation and curse as disturber of peace in the Middle East, occupier of the Arab territories and culprit of crimes against humanity.”

The statement threatened Israel and anyone who “dares hurt the dignity of its supreme leadership,” will face “merciless, thousand-fold punishment.”

“Israel would be well advised to think twice about the consequences [of] its smear campaign against the DPRK,” the statement also said.

Over the past few decades, North Korea has armed and trained countries and groups that are hostile to Israel, including Iran. Reports also have surfaced that North Korea  helped Syria build a nuclear reactor that was destroyed in an attack believed to be by Israel in 2007.

CAP: North Korean leader Kim Jong-un arriving for a military parade in Pyongyang, April 15, 2017. The picture was released the following day by North Korea’s official Korean Central News Agency.