US President Donald Trump has appointed Stephen Miller as his new Chief of Staff after the Republican Party's historic defeat in the midterm elections. Miller is one of the key people behind Trump's strict immigration policy. With Miller's appointment, a new face will take over the responsibility of this important post in the White House in place of Suzy Wiles. Wiles resigned from his post after the Republican Party lost control of both houses of Congress. This defeat has dealt a blow to the agenda of the last two years of Trump's tenure in the White House. Speaking to reporters, Trump said Wiles had "done a great job", but "sometimes we have to make changes." Miller, Trump's close aide and deputy chief of staff, will assume the new responsibility from Monday. 41-year-old Miller has also worked as a senior advisor during Trump's first term. Miller is among the few aides who did not leave Trump even after his defeat in the 2020 presidential election. After Trump returned to power last year, he started working with him again. On the social media platform X, Miller described Trump as "the greatest transformational political leader in American history." He said that Trump has single-handedly saved America from those who wanted to destroy it.