Knesset Speaker Yuli Edelstein and Iranian Foreign Minister Mohammad Javad Zarif never got a chance to be in the same room together at the MED conference on Middle Eastern Affairs in Italy amid escalating tensions between the two regional powers.

Zarif reportedly left his hotel room in Rome and left Italy on Friday ahead of Edelstein's remarks at the conference, prompting the senior Israeli politician to go after the top Iranian diplomat and his country over Tehran's alleged threat to Israel's security.

"He can't hear the truth, and deal with the fact that he represents a country that spreads hate and terror throughout the world," Edelstein wrote in a post on his Facebook page, accompanied by a clip of part of his remarks at the conference.

"You might ask me why I keep talking about Iran, perhaps you would say to the point of obsession. Well, ladies and gentlemen, as the son of two Holocaust survivors, when people threaten to kill me time after time, I tend to believe them. Call my warnings as you will, but the repeated Holocaust denial and anti-Semitic rhetoric from Iranian leaders aren't words alone," the politician said.

"Iran has been working hard to establish a presence in Lebanon, the Gaza Strip and Syria. As you all know, and the maps clearly show, Israel has no border with Iran, and yet Iran has consistently and insistently worked to develop a border with Israel," Edelstein added.

Shaming Italy for "deepening its cooperation with Iran" despite the Islamic Republic's alleged campaign of 'subversion' across the Middle East, Edelstein argued that Rome's decision to work with Iran was "harming the international effort to curb its terror."

The Iranian foreign minister spoke at the MED conference a day earlier, focusing on the Iran nuclear deal and the unilateral US decision to withdraw from the landmark agreement in May. Zarif ruled out fresh talks with Washington over the deal, saying there was no guarantee that any new agreement would last beyond the flight back to Tehran. "How are we to be confident that the signature stays on the paper?" he asked.

Zarif made no immediate response to Edelstein's comments, instead focusing his attention on prospects for peace efforts in Yemen, Syria and Libya and the recent US claims about a secret Iranian chemical weapons program.

Met with Italian FM on sidelines of #MED2018; reviewed bilateral ties & peace efforts in Yemen, Syria & Libya. Also met with large group of Italian businesses eager to engage with Iran. All riled by US bullying & determined to protect #JCPOA & to ensure Iran's economic dividends. pic.twitter.com/zvXY2prNyH — Javad Zarif (@JZarif) November 22, 2018

Earlier, Zarif slammed Israel's Mossad intelligence agency over what he said seemed to be a covert program aimed at "killing" the nuclear deal.

Incredible series of coincidences. Or, a simple chronology of a MOSSAD program to kill the JCPOA? pic.twitter.com/Xg5e0C5DAA — Javad Zarif (@JZarif) November 1, 2018

Traditionally rocky relations between Iran and Israel since the 1979 Iranian Revolution hit a new low in recent months, with Tel Aviv accusing Tehran of waging proxy wars against Israel in Syria and Lebanon and providing military and other support for Hamas in Gaza. Iran has denied Israeli allegations about a Syrian military presence, saying its assistance is limited to advisers aiding the Syrian government in its fight against terrorism. Iranian diplomats have also criticized the Israeli refusal to confirm or deny whether it possesses nuclear weapons, saying these suspected weapons pose the real threat to the region.