The Trump administration will not commit to designating the Islamic Revolutionary Guard Corps, or IRGC, Iran's elite fighting force, as terrorists, despite a congressional mandate to do so by the end of the month, according to multiple U.S. officials and other administration insiders who told the Washington Free Beacon that holdovers from the Obama administration are working to stymie the effort.

While President Donald Trump is expected to announce this week that he will not certify Iran as in compliance with the landmark nuclear deal, it remains unclear if he will follow through with congressionally approved plans to extend a terror designation to the IRGC, a move that has prompted Iran to threaten greater attacks on U.S. forces in the Middle East.

The IRGC is responsible for numerous terror attacks on American troops over the years and has played a key role in interfering with U.S. operations in Syria. A bipartisan consensus in Congress has already backed such a designation, but key Obama-era holdovers and top national security officials who have the president's ear are urging him to refrain, according to multiple sources who spoke to the Free Beacon.

Top lawmakers and insiders who spoke to the Free Beacon about the growing uncertainty over how best to hold Iran accountable for its terror activities expressed frustration over what they view as the administration's inability to follow through with its foreign policy promises, particularly as they relate to Iran, which has increasingly targeted U.S. forces with military action.

New reports emerged Wednesday afternoon that Trump's planned speech on Iran may be scaled back and not take place until Friday, if it does at all.

Trump last week signed new sanctions legislation mandating that the United States extend a terror designation to the IRGC, marking the first time in U.S. history a foreign country's military branch would be hit with such a designation.

However, the State and Treasury Departments would not confirm Wednesday that the administration intends to make good on this law, which was approved by Congress with bipartisan support.

The administration may be getting cold feet due to the objections of key U.S. officials and those in the Treasury Department who view such a designation as harmful to American companies that have business interests in Iran, where the IRGC controls a majority of the economy, sources said.

"The IRGC is responsible for wreaking havoc throughout the Middle East and, through its Quds Force, for killing hundreds of American troops in Iraq," Rep. Ron DeSantis (R., Fla.), a member of the House Foreign Affairs Committee and chair of its National Security Subcommittee, told the Free Beacon.

"The IRGC represents a quintessential terrorist group and should be designated as such," DeSantis said. "Whereas the Obama administration flew pallets of cash to the IRGC, the Trump administration should act to hold the IRGC accountable. Designating it as a terrorist group is a good first step."

Neither the State Department or White House would confirm to the Free Beacon plans to follow through with this designation, prompting speculation that the process may be held up over objections by Obama-era holdovers in the Trump administration who view the move as a shot at dismantling the former president's nuclear deal.

"Congress didn't ask the president to designate the full IRGC," according to one veteran Middle East policy advisor who lobbies Congress on Iran sanctions. "They told the president to do it by veto proof majorities. Obama holdover lawyers and his establishment staffers are telling him he can use loopholes to just go after some entities and circumvent Congress."

These same voices are continuing to advise Trump against decertifying Iranian compliance with the deal, despite the president's personal belief that the Islamic Republic has flagrantly violated what he has repeatedly described as a bad deal.

"These are the same people advising him to certify the nuclear deal, which was also rejected by bipartisan majorities in Congress," the source said. "They're wrong and if they stay wrong, lawmakers will eventually make it an oversight issue."

A State Department official declined repeated requests for clarification on what the administration intends to do about the IRGC, but told the Free Beacon officials remain "deeply troubled by Iran's longstanding provocative activities including its support for terrorism and destabilizing activities in the region."

"We are committed to holding Iran accountable for its behavior," the official said. "The United States retains the authority to respond to Iran's support for terrorism, human rights abuses, and destabilizing activities. The U.S. government constantly reviews information, through an interagency process, to evaluate potential sanctions violators for targeting under existing sanctions authorities."

A Treasury Department official did not respond to a request for comment on the matter.

Iranian officials vowed last week to strike U.S. forces and bases in the region if the Trump administration moves forward with extending a terror designation to the IRGC.

Rep. Sean Duffy (R., Wis.), a vocal opponent of the Iran deal, told the Free Beacon that Iran would be wise to back down from its threats.

"President Obama's terrible Iran deal predictably emboldened the Iranian regime to build up their military and antagonize the region," Duffy said. "Iran may have been able to bully our previous president, but the American people elected President Trump to stand up for the United States on the world stage."

"The Iranian regime is already on notice for being the world's largest state-sponsor of terror, and it would be wise for them to back down from their belligerent posture," Duffy added.