Trump to Announce Decision on JCPOA Tuesday

"I will be announcing my decision on the Iran Deal tomorrow from the White House," Trump wrote Monday afternoon.

Trump is weighing whether to continue waiving sanctions on Iran's energy and banking sector that were lifted as part of the 2015 agreement between Tehran and world powers.

He is widely expected to decide against extending the sanctions waivers, and in doing so, effectively leave the Joint Comprehensive Plan of Action (JCPOA), according to CNN.

Trump excoriated the agreement, even before winning the White House, as the "worst deal ever" and promised to tear it up on his first day in office.

One European diplomat said it seems fairly clear that the administration will walk away from the deal, and described the chances that the JCPOA will continue intact as "very small."

"It's pretty obvious to me that unless something changes in the next few days, I believe the president will not waive the sanctions," the diplomat said. "And that will have various consequences that I think we have yet fully to understand and spell out."

The implications of a US departure from the agreement aren't clear yet, but analysts have warned that it would send a message to other nations -- particularly North Korea -- about the reliability of the US as a negotiating partner.

Other analysts have pointed to the potential for a Middle East arms race if Iran also leaves the deal and re-starts its nuclear program.

Trump in January set a 120-day deadline for US lawmakers and European allies to “fix” his predecessor Barack Obama's main foreign policy achievement or face a US exit.

Since the historic deal was signed by Tehran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) in Vienna in July 2015, the International Atomic Energy Agency (IAEA) has repeatedly confirmed the Islamic Republic’s compliance with its commitments under the JCPOA, but some other parties, especially the US, have failed to live up to their undertakings.