US President Donald Trump will draw a red line on how long to give Hamas to accept an Israel-backed proposal to halt fighting in Gaza, the White House said on Thursday, without explicitly saying whether he would enforce a previously set deadline. Trump on Tuesday said he would give Hamas three to four days to accept the 20-point document, which calls on the militant group to disarm -- a demand it has previously rejected. Hamas is reviewing the proposal, a source close to the group said on Wednesday. Asked on Fox News to identify a point at which Hamas would be considered to have "walked away" from the proposal, White House spokeswoman Karoline Leavitt said: "Well, it's a very good...