Washington (CNN)Sen. Marco Rubio on Friday warned that a bad deal with Iran on its nuclear program "almost guarantees war," and defended his controversial amendment to the Senate's bill requiring congressional approval for the final deal.

"The argument the White House uses is if you're not in favor of this deal, you are in favor of war," Rubio said at the National Review Institute Ideas Summit. "I would argue that a bad deal almost guarantees war, because Israel is not going to abide by any deal that they believe puts them and their existence in danger."

Speaking to a crowd of conservative scholars and donors, the Republican presidential contender said that Iran would "exploit any loophole in a deal that it can find." He predicted a future in which Iran used the West's "short attention span" to snooker investors into pouring money into the country, which it would ultimately just use to attack the West.

Rubio mused that Iran would plot: "We'll blow up a bomb in one of their cities. We'll blow up their embassies in Latin America. We'll kill Americans. We're going to punish them -- a stronger Iran."

The final deal hasn't yet been released, but Rubio said he doesn't like what he's heard of the framework. And he defended his effort with Sen. Tom Cotton (R-Arkansas) to use a procedural tactic to try to force a vote on an amendment that would require Iran to recognize Israel's "right to exist."

That tactic has stalled activity on a bipartisan bill requiring congressional approval on the final deal, raising doubts about its passage.

"The criticism of that is that there are a bunch of countries in the Middle East that don't recognize Israel's right to exist, which is true," Rubio said. "But none of them are trying to build a nuclear weapon. And none of them have billions of dollars of sanctions, and if we lift those sanctions, we are handing over billions of dollars to the Iranian regime."

He also weighed in on immigration policy, accusing President Barack Obama's policy allowing children brought to the U.S. illegally to remain here of being abused by drug traffickers.

"I've had leaders of the Northern Triangle in Central America -- Honduras, Guatemala and El Salvador -- tell me that DACA was used by trafficking groups in the Northern Triangle to recruit people to send their children here illegally," Rubio said.

The senator again distanced himself from the failed 2013 bill that he helped shepherd through the Senate. He now backs a piecemeal approach to reform, and said the first step has to be securing the border. After that, Rubio floated the possibility of revising legal immigration limits every year "on the basis of what our economic needs are," and suggested after securing the border and modernizing the legal immigration system, there should be a pathway to citizenship for undocumented immigrants.

That pathway would require illegal immigrants have lived in the U.S. for a decade or longer and not violated any laws, and they would need to undergo a background check, pay a fine, start paying taxes and learn English.

"In exchange for all of that, what you would get is the equivalent of a non-immigrant, non-permanent work visa to be in the US," he said.

After holding that status for a period, Rubio said immigrants could apply for full citizenship.

By CNN