United Nations -- A White House team has returned to the Middle East for a tour of five friendly nations aimed at garnering support for the administration's still-vague plan to end decades of conflict between Israel and the Palestinians. President Donald Trump's senior adviser and son-in-law Jared Kushner, along with Middle East envoy Jason Greenblatt, met Jordan's King Abdullah in Amman on Wednesday.

The Trump administration's Iran negotiator Brian Hook, who also handles Mideast negotiations on behalf of the State Department, was also expected to be traveling with the team, making stops also in Israel, Egypt, Saudi Arabia and Morocco.

Their trip comes a month after Kushner attended a summit in Bahrain at which a proposed $50 billion Palestinian investment plan for the next 10 years was announced. Administration officials have called the proposed cash infusion the economic half of their Mideast peace plan. But they've revealed very little thus far about the political aspects of their plan -- which will need to address the disputes that have thwarted other peace initiatives for more than half a century.

Missing from the Bahrain discussion were two key delegations: the Israelis, who weren't invited, and the Palestinians, who boycotted the summit and have already rejected the Trump administration's peace effort as biased in favor of Israel.

At an open meeting of the Security Council last week on the Middle East, Palestinian Ambassador Riyad Mansour said the Bahrain conference had failed to acknowledge the "root causes of this conflict."

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Nonetheless, an administration official told CBS News the objective of this week's meetings in the region is "to continue the momentum of the successful Bahrain workshop on the economic plan."

At the Security Council meeting, Greenblatt said the U.S. negotiating team had been "clear and honest" about the need for both an economic and political plan to bring peace to the region. "There will be no economic prosperity without a political solution. But no political solution will succeed without a well-developed economic plan."

While the administration has revealed little in the way of detail on that "political solution," it's clear they intend to depart from the long-standing, internationally agreed parameters of the peace process.

"Let's stop kidding ourselves," Greenblatt told other Security Council nations, "If a so-called international consensus had been able to resolve the Israeli-Palestinian conflict, it would have done so decades ago. It didn't."

The U.N. Security Council has long been involved in negotiations to establish two states. Former U.S. Ambassador to the United Nations Nikki Haley, in her last address to the Council, implored members to heed the Trump administration's proposed peace plan. But the unveiling of that plan was stalled in the wake of the Trump administration's recognition of Jerusalem as Israel's capital and the moving of the U.S. Embassy to the holy city. Both moves were hugely contentious, and condemned by the Palestinians, who want East Jerusalem as the capital of a future state.

Some analysts -- in Israel in particular -- believe Greenblatt "gave a nod" to East Jerusalem as a potential future Palestinian capital when he noted in his remarks last week that "Jerusalem is a city of three world faiths," and that freedom to worship there must be protected. Two administration officials acknowledged to CBS News that his remark may have been a deliberate reference to the point.

In a wide-ranging interview with four news organizations including CBS News after his U.N. testimony, Greenblatt said that after the team's tour of the region, they would "have a better sense of what our next steps are."

In the interview, Greenblatt did lay out some more contours of the plan -- vague though they continue to be -- and how the administration will keep campaigning for it:

• On the timing: Mr. Trump's envoy said: "We have a decision to make - are we going to do it before the Israeli elections (in September) or after. Are we going to do it before they form a government or not. We haven't made that decision yet... We're protecting something extraordinarily delicate. We know that there's a lot of opposition to our effort, primarily from the Palestinian side. We are going to air it at a time that we think it has the best chance of success."

• On push-back at the U.N.: Some Security Council members, including Germany, blasted the U.S. stance as hypocritical, suggesting that Washington was keen to see international laws enforced when it suited American interests -- such as demanding a firm response to Iran's actions in the Persian Gulf -- while ignoring Israel's breaches for building new Jewish homes on occupied Palestinian territory.

German Ambassador Christoph Heusgen, directing his remarks at Greenblatt, said: "For us international law is not an a la carte menu."

Jared Kushner, (R) Senior Advisor to President Donald Trump, and Jason Greenblatt, advisor to Trump on Israel, attend the opening session of a Middle East security summit in Warsaw, Poland, in a Feb. 14, 2019 file photo. Getty

"I think that some of the Permanent Representatives misconstrued my remarks," Greenblatt said. "I did not throw international law into the garbage. That was very clear. We don't think, on this particular conflict, international law is clear. If we just hide behind diplomatic niceties and ambiguous resolutions and diplomatic words that really mean nothing, we're not going to achieve peace."

• On a two-state solution: "We don't think you could boil it down to a three-word slogan, so we stay away from the term," Greenblatt said. "We're well aware of what the Palestinian aspirations are. We're well aware of what the Israelis think that they can give. The hope is that it's interesting enough to both sides that they're willing to engage. I was interviewed last week on PBS and I said our plan does not contain a one-state solution."

• On the 1967 borders: For decades, the goal of the U.N.-backed international peace process has been to establish two separate nations; Israel alongside a new, independent Palestinian state with borders reflecting those that were in place before 1967, when Israel captured the West Bank and East Jerusalem.

"If that were achievable, I think we'd already have peace. It's not achievable. It's not a deal it seems that anyone has been able to achieve," he said. "One of the biggest challenges we have is the security risk to Israel. That doesn't mean we don't care about the Palestinians. It doesn't mean we don't want Palestinians to be safe and secure."

Greenblatt said the White House was hoping the international community would consider the new proposals, whatever they are, "with an open mind, and not revert back to the talking points and explain why they have issues." He said the White House believed "the criticism really needs to come from the Palestinians and the Israelis. It's not for America or the Europeans or anyone else to dictate how this conflict is resolved. We don't live there. Our lives aren't at risk there."

In the interview, Greenblatt conceded that his words may "irritate" some of America's allies, but insisted there was "nothing that I said that in our view wasn't truthful, and I think that everything that I said is a necessary step to eventually airing the plan, and if there's traction, getting to results."

CBSNews.com's Tucker Reals contributed to this report.