President Trump and Russian President Vladimir Putin's Helsinki summit was chosen to fall on a day when Trump would already be in Europe and Putin would be free from his World Cup final obligations in Moscow. The day that was picked, though — July 16 — is the day before the anniversary of a Malaysia Airlines flight being shot down over eastern Ukraine on July 17, 2014.
European investigators announced this spring that a Russia-based unit downed MH17, killing all 298 people on board, although Russia has denied the charges and Kremlin-linked publications have claimed without plausibility that Ukraine shot the plane down. Russia used its veto power in the United Nations to prevent an international tribunal from assembling to prosecute whoever was found responsible for the tragedy.
Trump has been criticized for his unwillingness to speak out against Russian aggression; while his staff has condemned Russia's annexation of Ukraine, and Trump himself slammed former President Barack Obama for being too soft in his response, Trump has also reportedly repeated Putin's talking points to other world leaders in defense.
Trump and Putin are set to talk about national security concerns as well as U.S.-Russia relations. It is unclear if Ukraine, or the MH17 disaster, will be discussed.