FILE - In this Monday, July 16, 2018 file photo, U.S. President Donald Trump, left, and Russian President Vladimir Putin, right, shake hand at the beginning of a meeting at the Presidential Palace in Helsinki, Finland. Throughout 2018, special cnvestigator Robert Mueller’s team investigated whether Trump's campaign colluded with Russia ahead of the 2016 election and whether the president obstructed the investigation. (AP Photo/Pablo Martinez Monsivais)