Several Republican presidential candidates criticized the Obama administration's decision to swap seven Iranian prisoners for The Washington Post's reporter Jason Rezaian and three other Americans on Saturday.

Some of them, including Sen. Marco Rubio (R-Fla.), accused the administration of not pushing hard enough for the American prisoners' release when the United States negotiated a deal with Iran last year. A group of 21 senators, led by Rubio and Sen. Mark Kirk (R-Ill.), sent a letter to Secretary of State John Kerry last year to demand the prisoners' unconditional release. Kerry has said that he repeatedly pushed for the men's release during negotiations.

On Saturday, Republicans said that Obama should not have given up Iranian prisoners because it made the United States look weak and that the U.S. prisoners should have been released without condition.

Shortly after the exchange was announced, Rubio said that while he was happy the Americans were coming home, the release would only encourage U.S. enemies to take more hostages abroad.

"They shouldn't have been in jail. I just saw Jason's brother on Tuesday night at the state of the Union. He's never been in jail, he did nothing wrong," Rubio told The Guardian's Sabrina Siddiqui. "Governments are taking Americans hostage because they believe they can gain concessions from this government under Barack Obama. It's an incentive for more people to do this in the future."

New Jersey Gov. Chris Christie, who has also spoken critically of the Iran deal, similarly said that the United States should not have had to make any concessions to get the Americans released.

"We shouldn’t have to swap prisoners, these folks were taken illegally in violation of international law and they should have been released without condition," Christie told WHOTV in Iowa. "But you know, the Iranians have treated this president with disrespect for years and he continues to take it. I would not take it as president."

Sen. Ted Cruz (R-Texas) celebrated the return of pastor Saeed Abedini, but still criticized the Iranian nuclear deal.

Praise God! Surely bad parts of Obama's latest deal, but prayers of thanksgiving that Pastor Saeed is coming home. https://t.co/rad1VcWUml — Ted Cruz (@tedcruz) January 16, 2016

Former neurosurgeon Ben Carson also praised the release of four Americans and attacked the Iran nuclear agreement. He pledged to withdraw from the agreement on his first day as president, if elected.

Such a critique is somewhat perplexing, given that the nuclear deal laid the foundation for the diplomacy and negotiations that led to the release of the prisoners.

Donald Trump also questioned the exchange, which came on the same day that sanctions were lifted on Iran, saying that Iran was getting more in the deal than the United States.

"They’re getting seven people, so essentially they get $150 billion plus seven, and we get four,” Trump said in New Hampshire, according to The Guardian. Trump added that he was happy the Americans were coming home.

Rep. Jared Huffman (D-Calif.), who represents Rezaian's family, said that Republicans who criticized the swap were naive.

"In a perfect world, of course, we would not have to negotiate, we would not have to compromise over the release of these people that we believe are completely innocent. But this is not a perfect world," he told The Huffington Post. "I think that the Republicans that are so predictably going to attack the administration over this deal are just so in denial about the complexity of our relationship with Iran and frankly the politics of the entire region."

Not every Republican presidential candidate was critical of the decision. Sen. Rand Paul (R-Ky.) told The Guardian that the release was “a sign that we need to continue to try to see if negotiations will work.” Paul also called Iran's decision to release the prisoners "a sign of hope."

Former Florida Gov. Jeb Bush (R) also tweeted that the Americans released never should have been held in the first place.

According to the HuffPost pollster, which averages publicly available polling data, Donald Trump leads his fellow rivals in the national Republican primary, with 37 percent.

PHOTO GALLERY Responses To Iran Deal