By Zachary Cohen, CNN

(CNN) -- A bipartisan group of more than 100 US national security experts -- including nearly 50 retired military officers and more than 30 former ambassadors -- is urging President Donald Trump to remain in the Iran nuclear deal as sources say it is becoming increasingly likely he will withdraw.

The statement titled "Keep the Iran deal -- 10 Good Reasons Why" calls on Trump to "maintain the US commitment to the Iran nuclear deal" as doing so will "strengthen America's hand in dealing with North Korea, as well as Iran, and help maintain the reliability of America's word and influence as a world leader."

"Ditching it would serve no national security purpose," the statement said.

Penned by a group that calls itself the National Coalition to Prevent an Iranian Nuclear Weapon, the coordinated message comes as US officials are taking a two-track approach to the deal -- negotiating with allies to make changes demanded by Trump even as they prepare to walk away from the international agreement.

Trump set a May 12 deadline -- the next date by which he has to waive sanctions against Iran or leave the deal -- for the US and its European allies to agree on changes to address what he sees as its flaws.

The President's thinking, officials say, is that if the US and Europe are united on amending the deal, the other signatories -- Russia and China -- will come along, and Iran will have no choice but to comply.

But Trump himself has dismissed the deal as "terrible," and recent changes within the administration giving Iran hawks John Bolton and Mike Pompeo significant influence on the issue, mean many officials in the US and Europe are bracing for Washington to abandon the agreement.

Against that backdrop, US officials leading the negotiations with European allies say that at the same time, they are readying contingency plans should Trump decide to pull the US out.

By releasing a joint statement on Monday, the group of more than 100 national security veterans join a shrinking contingency within the administration that has advised the President to remain in the deal -- which notably includes Defense Secretary James Mattis and Joint Chiefs Chairman Gen. Joseph Dunford.

Active duty four-star generals Joseph Votel and John Hyten have also advocated for staying in the agreement.

The group argues that maintaining a US commitment to the deal will not only enhance US and regional security by implementing unprecedented international monitoring of Iran's nuclear program but will also set a precedent for future dealings with emerging threats like North Korea.

"North Korea could not claim that the US abrogates agreements without cause and would be more likely to negotiate an end to its nuclear program," the statement said.

Remaining in the accord will also help strengthen US leadership on the world stage and bolster relations with key European allies, the group argues.

"US relations with major European allies, who all oppose US withdrawal, would be preserved for advancing US national security interests beyond the nuclear deal," the statement said. "The US will build credibility and retain influence with its negotiating partners to ensure strict implementation with the agreement, be able to lead efforts to strengthen it, or garner strong support for imposing additional sanctions if necessary."