For decades, the region stretching from Australia to Asia has been referred to in Washington as as the "Asia-Pacific." "But as Trump prepares for a five-nation Asian tour, White House officials and even the president himself are steering clear of that term and using 'Indo-Pacific' instead," writes AP's AP's Matthew Pennington.

Why it matters: "By using 'Indo-Pacific,' the administration wants to propagate the idea that it's a region that stretches far beyond China's backyard and the tiger economies of East Asia."