 -- In the coming days, President Donald Trump is up against another consequential deadline on the Iran nuclear deal, just months after vowing to tear it up if Congress didn't move to fix it.

By Friday, the president must either once again sign waivers on Iranian sanctions -- and keep the nuclear accord alive -- or refuse to sign, effectively terminating U.S. participation in the agreement and setting off an international crisis.

Despite the past recommendations of his national security team, it's something he has threatened to do repeatedly.

The waivers are on the nuclear sanctions the U.S. agreed to lift as part of the 2015 agreement between the U.S., Iran, the European Union, China, Russia, Germany, the U.K., and France. As part of America's commitment under the Joint Comprehensive Plan of Action, or JCPOA, they must be re-signed periodically for varying lengths of time; some come up every 90 days, others 120 or 180.

Trump has reluctantly done so nearly half a dozen times so far, usually while slapping Iran with new, non-nuclear sanctions that do not violate the deal.

But this will be the first time the president is faced with the decision since announcing his new Iran strategy in dramatic fashion last October -- when he threatened to terminate the deal unless Congress made some "fixes."

The sanctions waivers must be signed by close of business on Friday, January 12. As is customary, the Secretary of State has been designated to sign the waivers, so Rex Tillerson will be the one to notify Congress of the administration’s decision Friday -- but only after Trump consults with his national security team and makes the final call.

White House Press Secretary Sarah Sanders said on Tuesday that no final decision has been made, but she expects one in the coming days. Trump and his national security team are expected to meet again to discuss the issue this week.

In that big October speech, the president refused to certify the Iran nuclear deal, telling Congress that the sanctions relief to Iran was greater than the advantages to U.S. national security.

But certification is a requirement of U.S. law, not the JCPOA itself -- so nothing changed in the deal as, despite Trump's tough words, the U.S. still kept its commitments to it.

Instead, Trump threatened to "terminate" the deal if Congress didn't make changes, such as addressing Iran's ballistic missile program, which the agreement does not cover, or the expiration of certain limits on Iran's nuclear program.

The challenge, however, is that Congress did not write the deal and cannot now change it. Any changes they agree with the President to put into law could end up putting the U.S. in a material breach of the agreement -- with European allies already warning that certain changes would be unacceptable.

Either way, there’s been almost no movement toward a legislative fix since that speech, according to sources on Capitol Hill. Even if Congress does somehow come up with legislation that both appeases the president and doesn't violate the deal, it certainly won't be ready by the end of this week.

Instead, the President will have to make a decision before Friday -- sign the waivers and keep the deal alive with no fix in sight, or put the U.S. in violation and threaten an international crisis.

If the U.S. breaches its commitments, Iran might resume its uranium enrichment programs, sparking new concerns about a nuclear stand-off in the Middle East.

The regime in Tehran could also complain to the European signatories to the deal, who support its continued implementation and have advised the Trump administration against tearing it up or making any changes to it -- further driving a wedge between the U.S. and its historic European allies.