Iran vowed to maintain its nuclear infrastructure and threatened to boost its uranium enrichment capabilities just hours after announcing that it had agreed to a deal to halt some aspects of its contested nuclear program.

Iran and Western nations announced on Sunday that they had agreed to an interim deal to halt portions of Iran’s nuclear program in exchange for some $7 billion in sanctions relief.

Secretary of State John Kerry celebrated the interim agreement, which will officially begin on Jan. 20.

However, Iranian officials threatened to ramp up nuclear activities should they feel the West is violating the accord.

“We will in no way, never, dismantle our [nuclear] centrifuges,” Iranian Deputy Foreign Minister Abbas Araqchi told the country’s state-run television station on Sunday, according to New York Times reporter Thomas Erdbrink.

“Iranians endured sanctions for 10 years, resisted, so the world would respect our right to enrichment, this is now the case,” Araqchi was quoted as saying. “This game is played in our court. We cannot lose and return to enrichment as we wish.”

Araqchi reiterated that Iran has a right to enrich uranium, one of the key sticking points in the deal, and predicted that the deal has less than a 50 percent chance of success.

“We don’t need enrichment right from the Americans, who are they to give that right?” Araqchi said. President Barack Obama “said the upcoming talks have a 50-50 percent chance of success, I say its even less.”

Iran will continue to enrich uranium, the key component in a nuclear bomb, up to 20 percent levels until right before the deal takes effect, according to Araqchi.

“Iran will continue with 20 percent uranium enrichment by the end of the day on Jan. 19 and will suspend 20 percent enrichment on Jan. 20,” the Islamic Republic News Agency (IRNA) quoted him as saying.

Iran will immediately begin to see “targeted relief” from the economic sanctions as soon as the deal begins, according to Kerry.

“The $4.2 billion in restricted Iranian assets that Iran will gain access to as part of the agreement will be released in regular installments throughout the six months,” Kerry said in a statement. “The final installment will not be available to Iran until the very last day.”

The White House is refusing to release the official text of the nuclear deal, despite requests from reporters and members of Congress.

“I urge the White House to publicly release the text of the implementation agreement with #Iran for all to review,” Sen. Mark Kirk (R., Ill.) tweeted on Sunday.

Meanwhile, Iran’s parliament vowed to boost enrichment to 60 percent, very near the levels needed for a nuclear weapon, should the U.S. Congress pass a new sanctions bill currently up for debate.

“If the U.S. Congress approves any [more] sanctions against the Islamic Republic of Iran, the Islamic Consultative Assembly [the parliament] will accelerate the approval of a bill which requires the government to enrich uranium to the 60 percent grade,” Mohammad Hassan Asafari, a member of the parliament’s National Security and Foreign Policy Commission, told Iran’s Fars News Agency on Sunday.

Iranian Parliamentarians also vowed to end nuclear talks should the new sanctions pass.

“If the U.S. Congress doesn’t abide by the policies of the administration and approves new sanctions, the parliament will be ready to declare Iran’s exit from the nuclear negotiations with the Group 5+1” comprised of the United States, Russia, China, Britain, France, and Germany, Esmayeel Jalili, a top Iranian lawmaker, told Fars.

Kerry also came out against the new sanctions bill in his Sunday statement.

“I feel just as strongly that now is not the time to impose additional sanctions that could threaten the entire negotiating process,” he said. “Now is not the time for politics. Now is the time for statesmanship, for the good of our country, the region, and the world.”

Obama also opposed new sanctions on Sunday.

“Imposing additional sanctions now will only risk derailing our efforts to resolve this issue peacefully, and I will veto any legislation enacting new sanctions during the negotiation,” Obama said in a Sunday statement.

Kirk, one of the chief architects of the new sanctions bill, lambasted the nuclear deal and urged the administration to support his measure.

“Beginning January 20th, the administration will give the world’s leading state sponsor of terrorism billions of dollars while allowing the mullahs to keep their illicit nuclear infrastructure in place,” Kirk said in a statement. “I am worried the administration’s policies will either lead to Iranian nuclear weapons or Israeli air strikes.”

“It’s time for the United States Senate to pass common-sense bipartisan legislation now cosponsored by 59 senators to ensure this process leads to the peaceful dismantlement of Iran’s nuclear program,” Kirk said.

In addition to having the public support of 59 Democrats and Republicans in the Senate, sources said some 77 senators would vote in favor of the new sanctions measure should it come to a vote.