US President Donald Trump meets with Russian President Vladimir Putin at the G20 summit in Hamburg, Germany, July 7, 2017. (Photo: Carlos Barria/ Reuters)

Mr. Trump announced a change of mind on Twitter but stressed that an agreement with Russia on a ceasefire in Syria can happen and did happen. At a meeting on Friday on the sideline of the G20 Summit in Hamburg, Germany, Trump and Putin discussed forming "an impenetrable Cyber Security unit" to address issues such as the interference in national elections.