WASHINGTON - European Union leaders on Thursday said they'd re-affirm the Iran nuke deal, despite US President Donald Trump's refusal to recertify the accord. But if Washington pulls out, Iran said it would shred the deal. That leaves the deal in limbo, experts told Xinhua.

According to European press reports on Thursday, EU leaders will re-affirm that they are committed to the international accord of world powers.

That sits in sharp contrast to Trump's stance on the international agreement. Earlier this month, Trump failed to certify that Iran was playing by the rules stipulated in the international accord on Iran's nuclear program, and contended that the Islamic republic is in defiance of the agreement.

Trump has given Congress 60 days to decide whether to reinstate the sanctions on Iran that were lifted under the 2015 accord.

Trump's move neither scraps the deal not saves it, and there's a chance the international accord may remain intact. But the deal's future remains uncertain, and some believe it risks falling apart.

"The nuclear agreement is in danger of collapsing," Jim Phillips, senior Middle East research fellow at the Heritage Foundation, told Xinhua

"The Obama Administration promised too much and delivered too little," he said of the previous administration, which put together the deal.

"Then the Democrats in the Senate blocked debate on the merits of the deal and prevented a resolution of disapproval from being voted on, despite the fact that 58 of the 100 senators were opposed to it," he said.

Phillips' outlook for the deal's survival is dim.

"Congress is likely to re-impose sanctions, but if it doesn't, President Trump is likely to abrogate the nuclear agreement himself," Phillips said.

The deal, clinched in July 2015 between Iran and the six countries of Britain, China, France Russia and the United States, plus Germany, after a decade of negotiations, has seen Iran scale down nuclear projects in exchange for international sanctions easing.

Others do not necessarily forecast the death of the deal, but say there is much uncertainty on the horizon.

"The Iran deal is suffering a lot of duress right now. It is not clear how Trump will handle it because he has delegated the issue to Congress to handle," Brookings Institution Senior Fellow Darrell West told Xinhua.

"They could seek to impose new conditions, which would be very problematic for the European Union and Iran. Or legislators may be unable to agree, which could end up preserving the status quo," West said.

"For right now, it looks like there will be lots of uncertainty for a few months," West said.

Meanwhile, Thursday saw what experts said could become a war of words between the White House and Iran, as the Islamic Republic's Ayatollah in a speech called Trump "foul mouthed" and accused him a "pretending to be an idiot."

Experts said this may be the opening salvo of a war of words with Trump, as the US president is known to make impetuous, off-the-cuff remarks, especially via social media platform Twitter.

Phillips said: "I think US-Iran tensions are rising regardless of what happens with the nuclear deal."