A New York grand jury on Thursday indicted Donald Trump over hush money payments made to a porn star, making him the first ever serving or former US president to face criminal charges.

The historic indictment of the 76-year-old Republican -- who denies all wrongdoing in connection with the payments made ahead of the 2016 election that sent him to the White House -- is certain to upend the current presidential race in which Trump hopes to regain office.