U.S. President Donald Trump waves to staff members while walking on the South Lawn of the White House towards Marine One in Washington, D.C., U.S., on Thursday, Jan. 27, 2017. Trump threatened today to cancel his Jan. 31 meeting at the White House with Mexican President Enrique Pena Nieto if Mexico rules out reimbursing the U.S. for construction of a border wall. Photographer: Andrew Harrer/Bloomberg via Getty Images
