Mr Hassassian, who is a Palestinian General Delegate to the UK, said Trump’s plan to acknowledge Jerusalem as capital of Israel would be the “kiss of death” to the two-state solution.
White House officials last week said President Trump will recognise Jerusalem as Israel’s capital city on Wednesday, a move officials fear could spark a war in the Middle East.
Speaking on the Today programme, Mr Hassassian said: “At a time when the entire Middle East and the Palestinian Israelis need a certain breakthrough, a reengagement in negotiations.
“Here he comes to start a whole new episode of confusion, anarchy, distortion to the concept of a two-state solution and by you now announcing that he is declaring war in the Middle East.
“He’s declaring war against 1.5 billion Muslims, hundreds of millions of Christians that are not going to accept the holy shrines to be totally under the hegemony of Israel, let alone that East Jerusalem has always been known as the future capital of Palestine, let alone that it is under occupation.”
Donald Trump is expected to do a White House speech on Wednesday where he will direct the State Department to begin looking for a site for an embassy in Jerusalem.
The move is part of what is expected to be a year-long process of relocating diplomatic operations from Tel Aviv to Jerusalem.
But the President’s Middle East allies all warned against the major foreign policy move when Mr Trump called the leaders on Tuesday.
Turkey warned America it could sever ties with Israel if Donald Trump recognises Jerusalem as its capital today. Turkish President Recep Erdogan said: “Jerusalem is a red line for Muslims. We could go as far as cutting diplomatic ties with Israel over the issue.”
Hamas chief Ismail Haniyeh said: ”Our Palestinian people everywhere will not allow this conspiracy to pass, and their options are open in defending their land and their sacred places.”
Jordan’s King Abdullah warned the decision would have “dangerous repercussions on security and stability.”
Senior Trump administration officials said Trump’s decision was not intended to tip the scale in Israel’s favour and that agreeing on the final status of Jerusalem would remain a central part of any peace deal between Israel and the Palestinians.