Republican presidential candidate Ted Cruz took on a harsher tone against the Iranian regime as foreign policy is now set to take center stage in the Republican primaries, especially during the month of October, as world leaders gather for the U.N. General Assembly in New York.

In a speech at the Values Voter Summit in Washington on Friday, Cruz vowed not only to tear up the Iran nuclear deal on day one of his presidency but to also threaten the Supreme Leader with assassination.

“I will rip to shreds this catastrophic Iranian nuclear deal,” he said on his first day in office. “If you vote for Hillary you are voting for Iran to acquire nuclear weapons. If you vote for me, under no circumstances will Iran be allowed to acquire nuclear weapons.”

“And if the ayatollah doesn’t understand that, we may have to help introduce him to his 72 virgins,” Cruz added, referring to the Islamic extremists’ belief of what will await them in the afterlife upon martyrdom.

To date, after Scott Walker’s exit, Cruz and Rubio remain the only top-tier candidates to pledge to rip up the deal on day one. The two also remain top favorites in what has been dubbed as the ‘Adelson primary’ – the road to win over GOP mega-donor Sheldon Adelson. Former Florida Governor Jeb Bush, who unveiled his Jewish Leadership team on Friday, has called for a more moderate approach in the day after the international accord would be implemented. “It’s not a strategy to tear up an agreement,” Bush said during the 2nd Republican televised debate on September 16. “A strategy would be how do we confront Iran? And, the first thing that we need to do is to establish our commitment to Israel which has been altered by this administration. And, make sure that they have the most sophisticated weapons to send a signal to Iran that we have Israel’s back.”

Republican presidential frontrunner Donald Trump, as in the case on other issues, continued his mockery of the Iran deal but wouldn’t offer any alternative. Speaking before an enormous crowd at the Oklahoma State Fair Friday evening, Trump called the Iran deal “one of the dumbest contracts I’ve ever seen of any kind” that “was done by extremely stupid people.”

Trump said he would have threatened the Iranians to release of the four American prisoners before finalizing a deal. “Do us a favor, let these four guys go,” he said. “Please let ‘em go, let ‘em go now. You’re gonna have problems if you don’t, we’re gonna kick your a** if you don’t.”

Two attendees later expressed concern over Trump’s lack of knowledge on foreign policy issues including dealing with the Iranian nuclear threat. Speaking to The Oklahoma Daily, Kimmi Breece, a fair-goer who attended Trump’s speech, remarked, “I don’t think he can point Iran out on a map. I’m a little bit hesitant to believe anything that he said.”

“I just felt like he didn’t have a lot of knowledge on the situation,” another attendee told the local publication. “I felt like his approach really made him seem like a bully.”

But that didn’t stop the Trump campaign from suggesting that Senator Marco Rubio is the one that should not be trusted on foreign policy issues.

Continuing an escalating feud with Rubio, following 48 hours of back-and-forth jabs between the two candidates, Trump’s advisor and special counsel Michael Cohen insisted that Rubio doesn’t have the right to take a stance on issues beyond the borders of the United States.

“Marco Rubio doesn’t mean anything to [Trump],” Cohen told CNN on Friday. “And as far as foreign policy, what gives Marco Rubio the right to talk about foreign policy?”

After the CNN co-host pointed out that Rubio  serves on the Senate Foreign Relations Committee, Cohen responded, “And look where we are  as far as this country is concerned. We are a disaster in this country as far as foreign policy.”

“This is not a man who belongs in the White House,” Trump’s Jewish advisor added.

Meanwhile, a new TV ad by the ‘New Day for America Super PAC ‘supporting Ohio Governor John Kasich claims he is the only one out of the 15 Republican candidates with the experience to deal with a multitude of foreign policy concerns and crises that are certain to loom large over the November 2016 election, including threats from ISIS, Al Qaeda, North Korea, Iran and cyber attacks.

Kasich spent this Saturday talking foreign policy in Iowa. Addressing a forum hosted by the Americans for Peace, Prosperity and Security group at Morningside College in Souix City, Iowa, Kasich said the U.S. must stand with Israel and that if Iran violates the nuclear deal, sanctions should be replaced on Iran. “The military option is a high priority when it comes to preventing Iran from getting a nuclear weapon,” he said. “I don’t want to say any more than that because I may end up becoming president.”

He also suggested to put soldiers on the ground overseas to fight the Islamic State.