Sen. Tom Cotton (R., Ark.) on Tuesday said President Donald Trump should deny certification of the Iran nuclear accord when it comes up for renewal later this month, regardless of whether or not Tehran is in technical compliance, given its failure to prevent a nuclear Iran.

"Even if they were complying with it—even if it was fully verifiable they were complying with it, which it's not and which they aren't, it is still not in our viable national security interests because it does not block Iran's path to a bomb," Cotton said in an evening address before the Council on Foreign Relations.

Cotton, a member of the Senate Armed Services Committee, stopped short of calling for a complete withdrawal from the accord. Instead, he urged a renegotiation and pledged to work with lawmakers to "begin the work of strengthening it and counteracting Iranian aggression with the threat of sanctions and military action, if necessary."

Trump must decide by Oct. 15 whether to recertify Iran's compliance to the accord, which aimed to limit Tehran's nuclear activities in exchange for the lifting of economic sanctions related to the program.

The Trump administration has been weighing since April whether to scrap the deal despite disagreement from U.S. allies in Europe, who helped implement the agreement two years ago. Trump, who has long pledged to rip up the accord, told reporters last month he made up his mind on recertification, but refused to offer further details.

Cotton's remarks arrived just hours after Trump's top Pentagon advisers told Congress that Iran is in compliance with the pact.

Testifying before the Senate Armed Services Committee, Defense Secretary Jim Mattis said it is in the U.S. national security interest to remain in the nuclear deal. Joint Chiefs Chairman Gen. Joseph Dunford, who appeared alongside Mattis, also told the panel Iran "is not in material breach" of the deal and said the pact has "delayed the development of a nuclear capability by Iran."

Though Secretary of State Rex Tillerson has signaled Trump is open to renegotiating the deal rather than abandoning it entirely, Iran has ruled out the possibility of revisiting the agreement. President Hassan Rouhani threatened last month to "respond decisively and resolutely" if the United States chooses to blow up the accord.

But Cotton, who dined with Trump on Monday and said he discussed the accord with the president, called the regime's bluff and said Iran has shown throughout history it responds to U.S. sanctions and military force.

"The time for reviewing Iran policy is over, the time for choosing is here," Cotton said. "The president should decline to certify, not primarily on the grounds related to Iran's technical compliance, but rather based on the long catalogue of the regime's crimes and perfidy against the United States, as well as the deal's inherent flaws and weaknesses."