Tel Aviv has repeatedly warned that it would “never allow” Tehran to obtain nuclear weapons. Iranian officials say they have no intention of doing so.

Israel is the “biggest violator of human rights, the only holder of nuclear weapons in the region, and the most serious chronic threat to international peace and security,” Iranian Foreign Minister Mohammad Javad Zarif alleged in a Tweet on Quds Day, the annual Iran-sponsored international event meant to signal Muslim solidarity with Palestinians.

“Jerusalem Day is the day to revive Palestinian rights and for the occupation and settlers to disappear,” Zarif added, remarking that “the conspiracy of the racist deal of the century has shown that Washington is a hopeless partner of the aggressor.”

Zarif’s tweet came the same day that Iranian Supreme Leader Ayatollah Khamenei made a fiery speech promising to “support and assist any nation or any group anywhere” that struggles against Israel, and claimed that the “struggle to liberate Palestine” was “an obligation and an Islamic goal.”

In a series of tweets summarizing his remarks, Khamenei called Israel a “deadly, cancerous growth and a detriment” to the Middle East that would surely “be uprooted and destroyed.”

Zarif’s tweet’s have been less aggressive, with the diplomat going into damage control mode on Thursday over a Quds Day poster by the Iranian government which made a reference to a “final solution” for Palestine, which some American and Israeli Jews took as a reference to Nazi Germany’s “final solution” of killing millions of European Jews in the Holocaust in the 1940s.

Commenting on the poster, Zarif insisted that “final solution” would be found “at the ballot box, through a REFERENDUM,” and slammed anyone claiming otherwise.

Israeli officials shot back at Tehran later in the day Friday, with Prime Minister Benjamin Netanyahu warning Iran not to threaten Israel with destruction lest they “put themselves in a similar danger.”

Newly minted Defence Minister Benny Gantz similarly dismissed Khamenei’s remarks, calling them “arrogant” and “a sign of weakness.”

“As someone who is very familiar with the Iranian issue, and as someone who prepared the IDF’s operational capabilities, I would not suggest to anyone that they try and test us,” Gantz said.

The back-and-forth claims are the latest shots in a long-running back-and-forth war of words between the two powers over which of them poses a bigger threat to the region. Iranian officials say it’s Israel and its US allies, pointing to Tel Aviv’s stock of nuclear weapons and regular military operations against its neighbours. Israel, whose official policy is neither to confirm or deny its possession of nuclear weapons, accuses Iran of spreading terrorism throughout the region, of threatening Tel Aviv’s national security, and of pursuing nuclear weapons, a claim Tehran has repeatedly denied.