The move will punt the issue to Congress, which will have to decide on a way forward. 

Trump is expected to announce his decision Oct. 12, the Washington Post reported, but said he is expected to avoid recommending the U.S. reimpose sanctions on Iran. 

The National Security Council did not respond to multiple requests by Anadolu Agency for comment on this story. 

Trump has until Oct. 15 to certify Iran is in compliance with the landmark accord, and that the deal is in the U.S.' national security interest.

If he chooses to "decertify" the deal it would be a first step to the U.S. reimposing its international sanctions regime on Tehran, which would likely derail the 2015 Joint Comprehensive Plan of Action (JCPOA).

The agreement provided Iran with billions of dollars in sanctions relief in exchange for widespread curbs on and access to its nuclear program. 

Defense Secretary James Mattis told lawmakers Tuesday it is in the best intertest of U.S. national security to remain in the deal. 

"If we can confirm that Iran is living by the agreement, if we can determine that this is in our best interests, then clearly, we should stay with it," Mattis testified before the Senate Armed Services Committee. "I believe at this point in time, absent indications to the contrary, it is something the president should consider staying with."

During the same hearing, Gen. Joseph Dunford said he believes Iran is not in material breach of the accord, which he believes has delayed Tehran’s nuclear capability.

The White House said Trump's "team has presented a united strategy that the national security team all stands behind and supports. And the President will make that announcement soon.”

A unilateral U.S. exit from the agreement would likely have undesirable consequences for Washington -- isolating it from its negotiating partners that include close European allies, and potentially forcing Washington to sanction them if they continue to keep with the accord's parameters.