First: the Obama administration.
The efforts to determine the number of Palestinian refugees date back to 2012, when Sen. Mark Kirk submitted an amendment to the 2013 Appropriations Bill, requires the Ministry of Foreign Affairs to prepare a report determining the number of Palestinian refugees according to the criteria of those who lived in Palestine in 1946-1948, and immigrated as a result of the 1948 war,  the State Department completed the report in 2015 and removed part of it related to the confidentially in January 2018. The report classifies and determines the actual number of Palestinian refugees to about 20,000, not as the United Nations claims 5 million.
Congress approved on October 26, 2015 the bill “Combating incitement and terrorism in UNRWA” submitted by the MP “Elena Lehtinen” to require assistance to UNRWA in the absence of employees associated with terrorist organizations or have published a hostile speech or the use of schools speeches hostile to Israel and America, and the administration of the United States has to exert diplomatic efforts to encourage countries to refrain from funding if these conditions are not met. It called for a change in the definition of Palestinian refugees and transfer of responsibility for Palestinian refugees from UNRWA to the UN High Commissioner for Refugees.
Second: Trump management.
The Trump administration is currently completing the steps of the Obama administration. In this context, the administration and the Congress have started a series of steps, the most important of which are:
Foreign Affairs magazine reported correspondence between senior US officials in January 2018 to end the refugee status of the Palestinians by dismantling UNRWA to end the right of return and to bring the refugee issue out of any possible negotiations with the Palestinians.
MP David Cecilin submitted to Congress on May 21, 2018 the “UNRWA Issue” bill, citing its bias against Israel, and calling on the State Department to develop a detailed strategy with regard to US contributions to UNRWA over the next five years.
On July 19, 2018, MP Doug Lampburn submitted the “UNRWA Reform and Refugee Support” bill to define the Palestinian refugee as the person who lived between June 1946 and May 1948 in the British-controlled area and the person who was displaced as a result of the Arab-Israeli conflict of 1948, a person who has not accepted legal residency or nationality in another country, and UNRWA should provide assistance to those who meet the definition and their number is about 600,000 refugees.
Sen. James Lancelford has worked to draft legislation that redirects US funding away from UNRWA and other local and international agencies. The draft states that the US State Department will ratify by 2020 that the United Nations has ended its recognition of Palestinian refugees.
Third: the possible scenario.
In light of these facts and the reading of the bills submitted to Congress, the United States will work to announce its policy towards the Palestinian refugee issue in an attempt to impose it on the international community along the lines of the Jerusalem issue. This policy includes three steps:
Change the definition of the Palestinian refugee concept, so that it is limited to the displaced after the 1948 war without their children and grandchildren.
Publish a report on the number of Palestinian refugees, their number amounted according to Washington, 600 thousand after the war of 48, tens of thousands of them were left.
Redirecting aid to UNRWA, limited to the specified number, with the assistance of children and grandchildren through international humanitarian institutions, and the United States Agency for International Development (USAID).
Fourth, the political objectives of the United States:
US policy aims to achieve three goals:
The dismantling of the Palestinian refugee issue and the end of the “right of return” as one of the thorniest issues in the Palestinian-Israeli conflict, in a way that would allow Israel to renounce any responsibility to address the refugee situation.
Allow the US administration to remove the right to return from the negotiating table if it is resumed.
To transform the Palestinian issue from a political and humanitarian issue to a humanitarian one only, and to push other countries to increase their humanitarian funding to the Palestinians.
Rawabet Center for Research and Strategic Studies