Argentinia's President Mauricio Macri waves as he arrives at the airport in Hamburg, northern Germany on July 6, 2017 to attend the G20 meeting. Leaders of the world's top economies will gather from July 7 to 8, 2017 in Germany for likely the stormiest G20 summit in years, with disagreements ranging from wars to climate change and global trade. / AFP PHOTO / Christof STACHE