EXCLUSIVE: Jason Greenblatt spent 20 years as the top real estate lawyer for New York developer Donald Trump. He worked on numerous deals from his office in the gleaming Trump Tower on Manhattan's Fifth Avenue.

But on a summer day this week Greenblatt was in another gleaming skyscraper several blocks away from his old office, this time at the United Nations, working on a geopolitical deal that has proven elusive even to the most seasoned diplomats. He addressed the United Nations Security Council on reaching a comprehensive peace deal between Israel and the Palestinians, and he had some blunt words for an institution that for decades has failed to resolve the conflict.

"We know that the Palestinians have seen promises made by some, and not kept. But President Trump and his administration desire to make the lives of everyone involved better," Greenblatt said. "Peace will require honesty, and a willingness to consider new ideas as well as courage and hard compromises. This is a time for us to speak to each other candidly, not in stale slogans and talking points."

Greenblatt is the president's point man on peace in the Middle East, and in his address, Greenblatt called out the well-worn bromides of the international diplomats who have yielded little progress.

"We will only achieve peace by putting forth a plan that both sides hopefully will be interested enough and excited enough to engage on and negotiate on and reach the finish line," he told Fox News in an interview after his Security Council appearance. "We won’t achieve peace by constantly referring to the tired talking points to international law that isn't clear on the subject, to international consensus which doesn't exist on this particular subject."

But despite the odds, he is optimistic.

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"We want tremendous lives for the Palestinians. We want lives that mirror the lives of Israelis as long as we can keep everybody secure. We are not going to get there with slogans."

His U.N. visit came one month after the Trump administration sponsored a "Peace to Prosperity" workshop that was held in Bahrain. More than 300 officials, including those from Israel and Arab nations, mingled to chart out an unprecedented effort to bolster the Palestinian economy. The administration plan is to provide $50 billion for desperately needed economic development, that officials say would create 1 million jobs for the Palestinians and take the West Bank, and Gaza, into a new era as well as neighboring economies.

But the Palestinian Authority, led by Mahmoud Abbas, not only refused to negotiate...or even participate, they even briefly arrested a Palestinian businessman from Hebron because he attended the event. Abbas has broken off ties to the White House as a protest, in response to the administration moving the U.S. Embassy in Israel from Tel Aviv to Jerusalem last year.

"Not only did the Palestinian Authority boycott the conference themselves, they tried to undermine the conference by asking others not to go. What a tremendous opportunity that they missed. Our hope is though, that when they see the political plan, they'll be interested enough to realize that they shouldn't miss this opportunity," says Greenblatt. "I think we are at a unique time in history. We have a very unique president who's not only a huge supporter of Israel, a president who understands Israel’s security needs but a president who wants to help the Palestinians themselves."

He is confident that the Palestinian leadership will eventually come around and see that the admiration’s plans are in their interest.

"I think when they see the plan, they will see that. Nobody is here to force something on them that doesn’t work, but we are also, as you heard this morning in my remarks, direct enough to say what you've been promised is probably not achievable. Nobody can force a deal on either side but, similarly, the deal that you want is just not there, so the only way you are going to get better lives is by sitting down directly with the Israelis. None of us can get the Palestinians and the Israelis to agree on a deal if they don’t want to do that deal. It’s not for America, it’s not for the European Union, it's not for anyone who is interested in this conflict to make decisions for the Israelis or the Palestinians. We don’t live there, we don’t suffer there, we don’t fight there, we don't die there, it's really up to the two sides to do that."

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Looming over the effort is the shadow of Iran, and Tehran's continued terrorist funding of Hamas and Hezbollah. With that in mind, Greenblatt calls any progress toward peace, "Iran's worst nightmare." And he is convinced that the Palestinians and Israelis... want to end the decades of strife.

"In the last two and a half years I've met so many ordinary Palestinians," Greenblatt says. "They want better lives. I'm not saying they don’t want many of the aspirations that they have been promised. But they are just as talented as Israelis, just as eager to have successful lives like Israelis, and I believe that when they see the plan they will realize what lies ahead, what many benefits they can get from the plan. The Israeli side is the same. They just want to live safely and securely. They already have a great economy. They are frustrated, they are skeptical just like the Palestinians and I hope that they too realize that the compromises that we are recommending, suggesting, because ultimately it is up to their government as well, are worth doing."

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Greenblatt is heading back to the Middle East next week for follow up meetings on the plan. He will be accompanied by the president’s senior adviser and son-in-law, Jared Kushner and other officials. They will visit Israel, Egypt, Jordan, Qatar, Saudi Arabia, and the U.A.E.

The 60-page political plan for both sides has not yet been released. But Greenblatt is confident that by proposing bold new ideas, President Trump will achieve a success that has long been sought but not yet sealed.