WASHINGTON — Soon after President Barack Obama signed an executive order Saturday lifting sanctions against Iran for seeking to acquire nuclear weapons, Republican critics and the American Israel Public Affairs Committee (AIPAC) issued stark warnings as the July 2015 accord forged by the United States and world powers began taking effect.

Obama’s eight-page executive order comes after International Atomic Energy Agency (IAEA) inspectors confirmed Saturday that Iran has dismantled most of its nuclear program, living up to its commitments in the Joint Comprehensive Plan of Action (JCPOA). The move paves the way for Iran to re-enter the international finance system, which will free up Iranian assets estimated to be between $100 to $150 billion.

“Today cannot be the beginning of the United States and Europe turning a blind eye to the troubling threat of a nuclear-armed Iran,” Tennessee Senator Bob Corker said in a statement. “Now armed with an initial windfall of more than $100 billion, Iran will have vast new resources to continue sponsoring terrorism, threatening its neighbors, and funding its nuclear and missile programs.”

Corker, who is also the chairman of the Senate Foreign Relations Committee, urged the US administration and its European partners to ensure that any violations of the deal are met with “immediate consequences.” Moreover, he vowed that his committee will continue to maintain “vigorous oversight” of the deal’s implementation and will use its available tools to “impose new sanctions should Iran breach the terms of the agreement.”

This latest step — “implementation day” as it is called in the text of the JCPOA — also comes on the heels of Tehran releasing four American prisoners held in Iranian custody, including Washington Post correspondent Jason Rezaian, in exchange for seven people imprisoned or charged in the United States, according to US and Iranian officials. A fifth American prisoner was additionally released in a separate “humanitarian gesture.”

Senator Bob Corker (left), speaks while flanked by ranking member Sen. Bob Menendez during a Senate Foreign Relations Committee hearing on Capitol Hill, in Washington, DC, March 11, 2015 (photo credit: Mark Wilson/Getty Images/AFP)

Senator Bob Corker (left), speaks while flanked by ranking member Sen. Bob Menendez during a Senate Foreign Relations Committee hearing on Capitol Hill, in Washington, DC, March 11, 2015 (photo credit: Mark Wilson/Getty Images/AFP)

“While I am delighted that our citizens who have been unjustly held in Iran will be released back to the United States and reunited with their families, we need to understand more fully all the details and implications of this arrangement, including its timing,” Corker said.

Presidential candidate and Florida Sen. Marco Rubio issued his own statement castigating the deal’s implementation as providing Iran “much-needed funds to expand its regional aggression and its support to terrorist groups like Hezbollah.”

Invoking images of the 10 US Navy sailors’ detainment earlier this week and citing Iran’s testing of ballistic missiles earlier this month, Rubio said the deal “rewards bad behavior” and that injecting large sums of cash into the Iranian economy will bolster the rule of Syrian dictator Bashar Assad and foment the growth of the Islamic State terrorist group.

“The nuclear accord will subsidize Assad’s murder machine, the greatest single recruitment tool for the Islamic State,” Rubio said. “Fueling Iran’s regional ambitions and its support for Assad … will only cause ISIS to grow stronger, not weaker.”

He also vowed to “undo” the deal and “restore the sanctions” if elected to the White House, unlike former secretary of state and Democratic presidential frontrunner Hillary Clinton, who called the move “an important step forward in preventing Iran from obtaining a nuclear weapon.”

“Iran has dismantled centrifuges, disabled a reactor, and shipped out almost all of its enriched uranium,” she said in a statement. “These are important steps that make the United States, our allies, and the entire world safer. I congratulate President Obama and his team, and I’m proud of the role I played to get this process started.”

Hillary Clinton, April 1, 2015 in New York City. (Andrew Burton/Getty Images/AFP)

Hillary Clinton, April 1, 2015 in New York City. (Andrew Burton/Getty Images/AFP)

Nevertheless, she also said the United States “can’t take our eye off the ball.” If elected president, she vowed to “vigorously enforce” the agreement, confront any negative Iranian actions and “stand side-by-side with our ally Israel and our Arab partners.”

Meanwhile, AIPAC — which led a multimillion-dollar campaign to block the deal’s passage last summer — called Implementation Day a “dangerous moment for America and our allies.”

In a statement, the pro-Israel lobbying group bewailed Iranian actions in the past seven months, such as violating a United Nations ban on ballistic missile tests, increasing its support for Hezbollah, the Assad regime and other terrorist allies. It also lamented the IAEA closing its probe into Iran’s nuclear program last month.

“These failures to penalize Iran for its irresponsible behavior, violations of international restrictions and failure to come clean on its past nuclear activities hardly inspire confidence for strict implementation of the JCPOA,” the statement said.