President Trump announced on Tuesday that he would be pulling the U.S. out of the Iran nuclear deal, calling the agreement “defective at its core.”

“At the heart of the Iran deal was a giant fiction, that a murderous regime desired only a peaceful, nuclear energy program,” Trump said from the White House. “Today, we have definitive proof that this Iranian promise was a lie.”

Under the 2015 nuclear deal struck by the United States under the Obama administration, world powers, and Iran, sanctions against Tehran were lifted in exchange for Iran’s cooperation in restricting its nuclear program.

Following Trump’s comments, former President Barack Obama released a statement on Facebook, labeling the announcement “so misguided.”

“Walking away from the JCPOA turns our back on America’s closest allies, and an agreement that our country’s leading diplomats, scientists, and intelligence professionals negotiated,” Obama said.

He argued that the Iran deal, also known as the Joint Comprehensive Plan of Action (JCPOA), “is working” and “is a model for what diplomacy can accomplish.”

“The JCPOA is in America’s interest – it has significantly rolled back Iran’s nuclear program. And the JCPOA is a model for what diplomacy can accomplish – its inspections and verification regime is precisely what the United States should be working to put in place with North Korea,” Obama said. “Indeed, at a time when we are all rooting for diplomacy with North Korea to succeed, walking away from the JCPOA risks losing a deal that accomplishes – with Iran – the very outcome that we are pursuing with the North Koreans.”

His former vice president, Joe Biden, shared similar sentiments, calling the Trump administration's move "a profound mistake."

"It will isolate the United States from nearly every major world power," Biden said in a statement, adding that any talk about a "'better deal' is an illusion." The former VP added that "All it will likely accomplish is to put Iran back on the path to a nuclear weapon with no clear diplomatic way out."

Politicians on both sides of the aisle also reacted to Trump’s decision on the Iran deal.

Speaker of the House Paul Ryan, R-Wis., credited Trump for the decision, calling the announcement “a strong statement that we can and must do better.”

"From the beginning, the Obama-era Iran Deal was deeply flawed. Iran’s hostile actions since its signing have only reaffirmed that it remains dedicated to sowing instability in the region,” Ryan said in a statement. “The president is right to insist that we hold Iran accountable both today and for the long-term. There will now be an implementation period for applying sanctions on Iran. During that time, it is my hope that the United States will continue to work with our allies to achieve consensus on addressing a range of destabilizing Iranian behavior—both nuclear and non-nuclear.”

House Minority Leader Nancy Pelosi, D-Calif., echoed Obama’s response, saying Trump’s “decision to follow his misguided and uninformed campaign promise to destroy” the Iran deal “endangers global security and defies comprehension.”

“This rash decision isolates America, not Iran. Our allies will hold up their end of the agreement, but our government will lose its international credibility and the power of our voice at the table,” Pelosi said in a statement. “The President’s decision to abdicate American leadership during a critical moment in our effort to advance a denuclearization agreement with North Korea is particularly senseless, disturbing and dangerous.”

Sen. Marco Rubio, R-Fla., said he was “glad” that Trump pulled the U.S. “from the flawed Iran nuclear deal.”

Sen. Mark Warner, D-Va., tweeted that "withdrawing from the Iran deal makes the United States, and the world, less secure."

Ohio Gov. John Kasich called Trump’s decision “a mistake,” adding that it gave the U.S. “nothing other than to remove constraints on Iran’s ability to produce nuclear weapons.”

"France, Germany, and the UK regret the U.S. decision to leave the JCPOA," French president Emmanuel Macron tweeted. "The nuclear non-proliferation regime is at stake."

Israel "fully supports" Trump's decision, Israeli Prime Minister Benjamin Netanyahu wrote on Twitter. "The deal didn’t push war further away; it actually brought it closer. The deal didn’t reduce Iran’s aggression; it dramatically increased it."

Former Secretary of State Hillary Clinton called the move "a big mistake" that "makes America less safe and less trusted."

A follow-up tweet said that during her time leading the State Department, she "helped negotiate the crippling international sanctions that brought Iran to the table. It would be much harder a second time, now that our credibility is shot."

Fox News’ Alex Pappas, Nicole Darrah and Brooke Singman contributed to this report.