Trump can do several things:
* Stop funding UNWRA. UNWRA serves exclusively Palestinians and ignores all other refugees, making Palestinians World Best Paid Refugees. Plus, grandchildren of real Palestinian refugees of 48 are still paid even today - no other refugees has this option; 
* Stop following all Palestinian demands. Palestinian Arabs already have their own state, it is called Jordan. Israel owes them nothing, because lands that it now has were taken from Jordan and Egypt after these counties attacked Israel. Nobody asks Russia to return Konigsberg to Germany.
* The whole idea of creating a new Arab state  could be questioned. Arab League already has 22 states, enough to make UN ridiculously biased. The new Palestinian Arab state will not bring any benefits to the world: it will be poor, extremist, militant and hostile to Western civilization. May be peace will be achieved by returning Gaza to Egypt and splitting West Bank with Jordan.

Appeasing Palestinians does not work.