By Philip Blenkinsop, David Lawder and Stephanie van den Berg BRUSSELS/BANFF, Canada/THE HAGUE (Reuters) -U.S. President Donald Trump threatened on Friday to ratchet up his trade war again, pushing for a 50% tariff on European Union goods starting June 1 and warning Apple he may slap a 25% levy on all imported iPhones bought by U.

Apple has become a frequent target for Trump, a factor that has held the stock back as other big tech companies have rebounded over the past month.