ISTANBUL—U.S. President Donald Trump will travel to Ankara, Turkey, to attend the NATO summit on July 7 and 8, where leaders are expected to review progress on the alliance’s defense spending commitments and burden-sharing goals. Hosted by Turkish President Recep Tayyip Erdogan, the summit brings together the leaders of NATO’s 32 member states amid continued pressure from the Trump administration for allies, particularly in Europe, to increase defense spending and assume a greater share of the alliance’s security responsibilities. Trump’s Schedule Trump is expected to arrive in Ankara on the afternoon of July 7, where he will be welcomed by Erdogan with a state arrival ceremony and honor guard review. The two leaders are scheduled to hold a bilateral meeting before joining the NATO leaders’ social dinner, White House spokeswoman Anna Kelly told reporters during a call previewing the summit....