Benjamin Netanyahu's aides fear that U.S. President Barack Obama will "surprise" the prime minister with unanticipated ideas and demands at the leaders' upcoming meeting in Washington on May 18.

A political source in Jerusalem said that Netanyahu's associates have been recently discussing a scenario in which Obama makes unequivocal demands on issues like West Bank settlement construction, illegal outposts and negotiations with the Palestinians.

The aides also fear a public clash between the two premiers, such as during a news conference or in comments the pair make, in which their differences will be aired.

A number of Netanyahu's aides are set to head to Washington and Europe next week for meetings with senior White House officials to prepare the ground for the prime minister's visit.

Netanyahu's strategic adviser Ron Dermer will meet with senior White House and State Department officials while in the U.S. next week for the annual conference of the American Israel Public Affairs Committee.

The source's comments came after officials in Jerusalem were themselves surprised by a report in the L.A. Times Monday that the Obama administration has asked Congress to amend U.S. law to enable the Palestinian Authority to receive federal aid even if Hamas joins a unity coalition.