Watch: Paul Ryan admits something about Obama's Iran Deal that no conservative wanted to hear

House Speaker Paul Ryan said on NBC's "Meet the Press" Sunday that the Obama administration's nuclear agreement with Iran is likely to stay in place, despite multiple campaign promises by President Donald Trump to repeal the deal once in office.

"A lot of that toothpaste is already out of the tube," Ryan told host Chuck Todd in an interview aired Sunday. "I never supported the deal in the first place. I thought it was a huge mistake, but the multilateral sanctions are done."

"I don't think you're going to go back and reconstitute the multilateral sanctions that were in place," he added. "So I think the key is to rigorously enforce this deal."

Ryan went on to express his desire for the Trump administration to ramp up sanctions against the Islamic republic.

"But also, remember, they're testing ballistic missiles. They're still the largest state sponsor of terrorism in the world. Human rights abuses galore," Ryan explained. "And so those are where I think we also need to ratchet up sanctions."

"I think what this administration is doing, which I agree with, is saying, 'We have a new administration, and we're going to hold you, Iran, to account,'" Ryan said. "This last administration did not do that."

When asked if he thought Iran would retaliate against the U.S. if the Trump administration increased sanctions, Ryan cynically replied that things can't get much "worse" with Iran because the U.S. is "already appeasing" the country.

The Trump administration issued new sanctions on Iran last week after the country continued testing their medium-range ballistic missiles, which violates United Nations sanctions.

More from NBC News:

he sanctions targeted three networks comprising 13 people and a dozen entities including a group affiliated with the Iranian Revolutionary Guards Corps working with the terrorist group Hezbollah. The Trump administration maintains that none of these designations violate the Iran nuclear deal.

Still, Iran continued holding military exercises over the weekend in defiance of Trump, threatening to drop missiles on their enemies.

National Security Adviser Gen. Michael Flynn officially put Iran "on notice" last week after the country continued testing their missiles.

Watch Ryan's comments about Iran below: