President Donald Trump addressing the United Nations General Assembly on September 19 in New York City. Drew Angerer/Getty Images

President Donald Trump listed a set of grievances in a press release on what the White House called its "new strategy for Iran" early Friday morning, hours before his administration was expected to announce whether he would decertify the 2015 Iran nuclear agreement.

Trump reluctantly certified the landmark Joint Comprehensive Plan of Action twice since he took office in January. He is required by law to review the deal every 90 days.

Certification is an acknowledgment that Iran is abiding by the terms of the deal and that the deal supports US interests. He signaled in July that he had serious reservations about approving the agreement a third time and argued that it had been one of the "worst deals in history." A decision to decertify the deal would not end the deal outright but would force Congress to decide whether to renew sanctions on Iran that would violate the agreement.

"The Iranian regime has displayed a disturbing pattern of behavior, seeking to exploit loopholes and test the international community's resolve," the White House statement said, apparently referring to Iran's continued tests in its ballistic-missile program. "This behavior cannot be tolerated; the deal must be strictly enforced."

"The reckless behavior of the Iranian regime ... poses one of the most dangerous threats to the interests of the United States and to regional stability," the statement continued. "The [Obama] Administration's myopic focus on Iran's nuclear program to the exclusion of the regime's many other malign activities allowed Iran's influence in the region to reach a high-water mark.

"The Trump Administration will not repeat these mistakes."

Trump vehemently criticized the nuclear deal throughout his 2016 presidential campaign.

The International Atomic Energy Agency — a United Nations watchdog tasked with inspecting nuclear programs — believes that Iran does appear to be in compliance with the nuclear agreement.

A man looking at Iranian-made missiles at Holy Defence Museum in Tehran, Iran, in 2015. Reuters

Outside the agreement, however, Iran has continued to provoke the US by testing ballistic missiles, albeit with lackluster results, and has been accused of supporting terrorist organizations like Hezbollah.

Trump therefore has said Iran has not "lived up to the spirit of their agreement," which he said in his most recent statement was to make "positive contributions to 'regional and international peace and security.'"

World leaders have urged the US president to stay on board with the deal, which includes several other countries.

"It's imperative that Europe sticks together on this issue," German Foreign Minister Sigmar Gabriel said, according to Reuters. "We also have to tell the Americans that their behavior on the Iran issue will drive us Europeans into a common position with Russia and China against the USA."

In addition to world leaders and scores of foreign-policy experts who say that certifying the Iran deal is in the US's best interest, members of Trump's Cabinet have done the same, departing from Trump on the matter. Both Secretary of State Rex Tillerson and Defense Secretary James Mattis were pressuring Trump to recertify the agreement, much to Trump's chagrin, The Washington Post reported on Wednesday.

"If we can confirm that Iran is living by the agreement, if we can determine that this is in our best interest, then clearly we should stay with it," Mattis told the Senate Armed Services Committee earlier this month. "Absent indications to the contrary, it is something that the president should consider staying with."