Representatives from two wealthy Gulf states, the United Arab Emirates and Saudi Arabia, announced on Tuesday that they will attend the economic gathering next month to roll out President Trump's Middle East peace plan.Driving the news: The UAE's Ministry of Foreign Affairs and International Cooperation said in a statement that the UAE would send a delegation to Bahrain at the end of June to participate in what the Trump administration is calling an "economic workshop." Saudi Arabia announced that its Minister of Economy and Planning will attend as well.Key quotes from the statements:"The UAE supports all international efforts aimed at supporting economic progress and increasing opportunities in the region, and alleviating the suffering of people in the region, particularly our brothers in Palestine.""His Excellency's participation is in continuation of Saudi Arabia's firm and supportive positions for the brotherly Palestinian people, and for achieving stability, growth and decent living, and achieving its hopes and aspirations..."Why it matters: Trump and his son-in-law and senior adviser Jared Kushner — who has led the administration's Israeli-Palestinian peace team — revealed on Sunday that the U.S. would organize an "economic workshop" to develop ideas and proposals to invest in Palestinians and other Arabs.Palestinian leaders immediately dismissed the announcement, saying the Americans hadn't told them about it in advance and that Kushner's team, with whom they haven't had formal discussions in more than a year, was trying to buy them off.Palestinian leadership has already declared Kushner's plan dead on arrival and said the Trump administration doesn't care about the Palestinians' political aspirations — to have their own state, independent of Israeli interference, with a capital in East Jerusalem.Since taking office, Trump has made a number of moves that have alienated the Palestinians. He relocated the U.S. embassy in Israel to Jerusalem. He slashed all U.S. aid to the Palestinians including to hospitals in East Jerusalem. And he shut down the Palestinian diplomatic office in Washington.What's next: Trump's Middle East peace team is presenting the economic plan in late June as the first in a two-part rollout. They say the political plan — which will deal with the division of land and how it will be governed — will come later. They haven't said when they will release the political plan.In his public appearances, Kushner hinted that when the Palestinians see his final proposal they will be pleasantly surprised. There have been no reliable leaks of what's in the plan, so Palestinian leadership has drawn its assessment based on the moves the Trump administration has already made. They say the Trump team is made up of dishonest brokers and their plan has no hope of succeeding.Between the lines: The Trump negotiating team has built strong relationships with the Gulf states, which have appreciated the president's tougher stance against Iran. The Gulf states' attendance at the economic summit gives the administration hope that if they present a plan that the wider region considers reasonable then Palestinian leadership will ultimately come back and negotiate.But the UAE statement made clear that while they welcome a conversation about economic investment, they consider the political solution crucially important."The UAE reiterates its support for the establishment of a Palestinian state with East Jerusalem as its capital,'' the Ministry reportedly said in its statement.Go deeper: White House launching Israeli-Palestinian peace plan next month in Bahrain