Members of Trump's team, including Secretary of State Rex Tillerson and Treasury Secretary Steve Mnuchin, cite Iran's "malign" activity in the region as a violation of the agreement.
Every 90 days the president has to notify Congress as to whether he believes Iran is complying with the accord and if the lifting of sanctions is in the interest of the American people.
News reported the White House briefed lawmakers Wednesday on the pending decision and those who left were convinced the Obama-era nuclear deal would get decertified.
Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff, told the Senate Armed Services Committee last week that Iran "is not in material breach of the agreement".
Republicans have complained that the deal delays Iran's nuclear ambitions but could allow Iran to resume its nuclear program after certain restrictions expire.
"If we pass the message that with every change of administration in Washington or elsewhere deals are thrown away and renegotiated, no one would negotiate with any administration ever and any deal would be exposed to be renegotiated every term".
Since taking office, the Trump administration has also signed multiple waivers for nuclear sanctions against Iran. He would not say whether he would be open to other changes, stressing new conditions might violate the deal. Engel, the top Democrat on the Foreign Affairs Committee, said unwinding the agreement would send a risky signal to allies and adversaries alike. He also wants to toughen language on ballistic missiles and inspections. "Once it was entered into, once it was implemented, we want to see it enforced".
The certification would also demand that the intelligence community produce judgments on a wide range of Iranian behaviour that is not covered by the nuclear deal, including ballistic missile testing and development, support for Lebanon's Hezbollah movement and Syrian President Bashar Assad and threats to Israel and the Mideast more broadly, according to the drafts.
It's not clear whether America's European allies would go along with a renegotiation, either.
Speaking at an worldwide conference on enhancing nuclear safety in Rome, Salehi said that Washington's recent "delusionary negative postures do not augur well" for keeping the deal intact.
Federica Mogherini, while talking to PBS TV channel, on Wednesday, highlighted Iran's full compliance with the 2015 deal.
What happens if Trump decertifies the deal? If those sanctions are put back into place, the JCPOA would be considered breached.
How would the European Union and Iran react to a possible US withdrawal? That could include Iran pulling out of the deal as well and restarting uranium enrichment activities, or Iran could stay in the deal and try to drive a wedge between the USA and its allies.
Trump will use an executive order to declare Iran's Islamic Revolutionary Guard Corps (IRGC) a terrorist organisation.
On Wednesday, head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi said that Iran is considering "various scenarios" in response to Trump's "probable withdrawal" from the global nuclear deal. "It doesn't try and do more. that needs to be understood and recognised in Washington".
However, the European signatories have said they were ready to discuss how it can be bolstered by stiffer measures aimed at Iran's missile programme, and what nuclear agreement might follow the JCPOA.
But it could be hard to get both Iran and its ally, Russia, back to the table for a new round of talks.