Ted Cruz
Ted Cruz Reuters

Republican presidential hopefuls voiced their support for Israel on Thursday, with promises to scrap President Barack Obama's controversial nuclear deal with Iran.

All 14 Republican contenders for the White House are taking part in the presidential forum sponsored by the Republican Jewish Coalition, a group funded by conservative billionaire casino magnate Sheldon Adelson.

Texas Senator Ted Cruz, who recently has been climbing in presidential polls, said he would make scrapping the nuclear deal the first order of business after assuming office following the next November's White House vote.

"If I am elected president, I have pledged on the very first day in office to rip to shreds this catastrophic Iranian nuclear deal," he said of the agreement with the leading state sponsor of terror.

Cruz stated that Obama's former secretary of state Hillary Clinton, who is running to succeed her ex-boss in the White House, would be equally catastrophic were she to become America's next commander-in-chief.

"If you vote for Hillary Clinton, you are voting for the Ayatollah Khamenei to have nuclear weapons," he said, in remarks echoed by his fellow Republican presidential contenders.

Obama has had a rocky relationship with Israeli Prime Minister Binyamin Netanyahu, and Republican critics accuse him of not doing enough to support the Jewish state and of making too may concessions to Iran in the recently concluded nuclear accord.

Another senator campaigning for America's highest office, Florida Senator Marco Rubio - who also has seen a marked rise recent polls - invoked recent terror attacks by Islamist extremists around the globe, vowing to stand up "to those who single out Israel."

Rubio also called the move by the European Union to label Jewish goods imported from Judea, Samaria, eastern Jerusalem and the Golan Heights an anti-Semitic decision.

"We must not separate the threat to Jerusalem and Tel Aviv from the threat to Paris, or London, or Washington, or even Miami," Rubio said, also criticizing a rise in anti-Semitism in Europe.

"Discriminatory laws that apply only to Jews are now being written into European law for the first time in more than half a century," the Florida senator said, to sustained applause.

He joined with Cruz in declaring that if elected president, he would move Washington's embassy from Tel Aviv to Jerusalem, the 3,000-year-old capital of the Jewish people.

Lindsey Graham, a US senator from South Carolina and former military attorney, joked that as president "I may have the first all-Jewish cabinet in America."

On a serious note, he insisted that on the topic of defense of Israel, his bona fides were second to none.

"ISIL will be destroyed, Iran will be defanged," under his administration, the senator proclaimed, using an alternate acronym for Islamic State (ISIS).

Graham also used his remarks to take a potshot at billionaire real estate mogul Donald Trump, who for months has been leading the field of Republican hopefuls despite a succession of controversial and inflammatory statements that pundits predicted would sink his campaign.

"I believe Donald Trump is destroying the Republican party's chance" to claim the White House, he said.

Trump gave an interview on Thursday, stating forcing peace talks on Israel and the Palestinian Authority (PA) is at the top of his priorities.

He also placed the onus for the lack of peace on the Jewish state, saying, "a lot will have to do with Israel and whether or not Israel wants to make the deal - whether or not Israel's willing to sacrifice certain things."

AFP contributed to this report.