President Trump left the G7 after firming up a trade deal with the United Kingdom. But he hinted at roadblocks on other fronts, saying Tuesday that Japan was being "tough" in trade talks and the European Union has failed to offer a fair deal.

Japan's top trade negotiator Ryosei Akazawa said on Friday that trade negotiations with the U.S. "remained in a fog" despite efforts by both sides to seek an agreement.

Japan has reported its exports fell in May as shipments of autos to the U.S. dropped nearly 25% from a year earlier due to higher tariffs imposed by President Donald Trump.