WASHINGTON (CNN) -- While President Barack Obama hailed the interim agreement to slow Iran's nuclear program as an "important first step," some lawmakers were skeptical about the deal on Sunday, including members of Obama's own party.
Both Republicans and Democrats were cautious about the agreement's provision to loosen sanctions against Iran. A few called for another round of sanctions to be passed immediately, while more urged a backup plan of that would impose new sanctions in six months if Iran fails to hold up its end of the deal.
Republicans were especially quick to pound the Obama administration Saturday night; Sen. John Cornyn, for example, argued the President's team was desperate to do anything to distract from the disastrous rollout of the HealthCare.gov website.
As more lawmakers took to the airwaves on Sunday morning, it became clear that the administration will have plenty of work to do in persuading Capitol Hill to have faith in the negotiating process.
Sen. Chuck Schumer, an important Democratic voice on Iran, said the deal disproportionately favors Iran, and he predicted bipartisan support in Congress for new sanctions.
"This disproportionality of this agreement makes it more likely that Democrats and Republicans will join together and pass additional sanctions when we return in December. I intend to discuss that possibility with my colleagues," the senator from New York said.
But Secretary of State John Kerry argued the lightened sanctions are not much of a boost for Iran. The deal says that the U.S. will provide $6 billion to $7 billion in sanction relief - just a drop in the bucket compared to the roughly $100 billion in foreign exchange holdings that are inaccessible to Iran.
"The basic architecture of the sanctions is staying in place. There is very little relief," Kerry said on CNN's "State of the Union."
In July, the House passed a bill with overwhelming bipartisan support that broadened sanctions against Iran. Rep. Eliot Engel, a New York Democrat and ranking member of the House Foreign Affairs Committee, said the sanctions have been working and the new agreement "makes it very difficult to continue the sanctions."
"I think we could have played good cop, bad cop. And Congress really believes that sanctions should happen," he said.
"I do think sanctions should always be hanging there because that's what brought Iran to the table in the first place," he added. "I don't think you make them bargain in good faith by going squishy."
Others called for ratcheting up sanctions in six months, unless Iran proves that it's carrying out its part of the deal, which includes reducing the level of its uranium enrichment, halting the production of new centrifuges, and freezing essential work on its heavy-water reactor under development at Arak.
"You will see the Congress have new sanctions that will be delayed for six months," Sen. Lindsey Graham, R-South Carolina, said Saturday night on CNN. "But we will define what success will look like before the sanctions can be waived in the future. So, the Congress is going to be focusing on the outcome."
Kerry, meanwhile, said he was confident the Congress will come to find "that this deal actually has a great deal of benefit in it."
"I look forward to going up and working with our colleagues on the Hill in order to try to persuade them that this is not the moment to increase sanctions," he said Sunday on ABC's "This Week."
Some lawmakers were also furious that Iran will be allowed to continue to enrich uranium while the talks go on for the next six months.
"I would have thought that (discontinued enrichment) should be a prerequisite to any kind of talks - without asking them to dismantle any of their centrifuges. So that's disappointing," Engel said.
The agreement requires Iran to dilute, to at or below 5%, half of its stockpile of near-20% enriched uranium and convert the rest to a form not suitable for further enrichment before the end of the initial phase of the deal.
Sen. Bob Corker, R-Tennessee, argued Iran is interpreting the deal as a green light for the right to enrich uranium --- a right the U.S. does not recognize for Iran.
"If you see the reaction in Iran right now, I mean, they're spiking the football on the end zone, saying that, look, we've consolidated our gains, we've relieved sanctions, we're going to have the right to enrich," he said.
Kerry acknowledged that the agreement doesn't completely tear down Iran's nuclear program, but he said dismantlement is "the next step" in negotiations.
"While we go through these next six months, we will be negotiating the dismantling," he said on ABC. "But you can't always start where you want to wind up."
Rep. Mike Rogers, chairman of the House Intelligence Committee, said Sunday that by loosening sanctions, the deal chisels away at the United States' leverage in the negotiations and gives Iran a "permission slip" to continue to enrich uranium.
"What have we done? We have taken away the one thing - we've given them just enough breathing room, the one thing that brought them to the table," the Michigan Republican said on "State of the Union."
Rogers pointed to Iran's role in terrorist activities in recent years, saying Tehran hasn't signaled it has abandoned those practices.
"We have just rewarded very bad and dangerous behavior," he said.
"We may have just encouraged more violence in the future than we have stopped. That's why I hope we reconsider where we're at," he added.
Sen. Marco Rubio, R-Florida, also argued the agreement sets a bad precedent.
"By allowing the Iranian regime to retain a sizable nuclear infrastructure, this agreement makes a nuclear Iran more likely," he said. "This agreement shows other rogue states that wish to go nuclear that you can obfuscate, cheat, and lie for a decade, and eventually the United States will tire and drop key demands."
Lawmakers weren't all doom and gloom on the new agreement. Senate Intelligence Committee Chairwoman Dianne Feinstein supported the agreement Sunday. "By any standard, this agreement is a giant step forward and should not be undermined by additional sanctions at this time," the California Democrat said in a statement.
Sen. Carl Levin, a Democrat from Michigan and chairman of the Senate Armed Services Committee, said in a statement he supports the deal and described it as a "realistic, practical way to freeze Iran's nuclear program for six months while we seek a long-range diplomatic end to Iran's nuclear weapon ambition."
Rep. Adam Smith, a Democrat from Washington and the ranking member of the House Armed Services Committee, also came to Obama's side.
"The deal announced today is a positive step in the right direction, and I applaud the Administration for making progress on this impotent national security issue," he said in a statement.
House Minority Whip Steny Hoyer called it a "marginal improvement" but still urged caution. On CBS's "Face the Nation," he supported the idea of moving forward with new sanctions but delaying them for six months.
Sen. Mark Kirk of Illinois, a moderate Republican who has been pushing for more sanctions on Iran, was slightly conciliatory, saying he would support holding off on sanctions for six months while the international community makes sure Iran carries out its part of the agreement.
Acceptance is not agreement, however, and Kirk made clear his distaste for the deal.
"This deal appears to provide the world's leading state sponsor of terrorism with billions of dollars in exchange for cosmetic concessions that neither fully freeze nor significantly roll back its nuclear infrastructure," he said.
House Speaker John Boehner was also more measured in his statement Sunday morning.
"The interim deal has been and will continue to be met with healthy skepticism and hard questions, not just of the Iranians, but of ourselves and our allies involved in the negotiations," he said. "Iran has a history of obfuscation that demands verification of its activities and places the burden on the regime to prove it is upholding its obligations in good faith while a final deal is pursued."
Kerry sought to underline a key ingredient in the agreement---that Iran would be held accountable.
"We're not just going to verify, or trust and verify, we're going to verify and verify and verify," he said on CNN. "We have to know to a certainty so that Israel, Gulf States, ourselves, nobody can be deceived by what is taking place."