The U.S., heading into a major summit of advanced economies, is warning that currency intervention by countries such as Japan won't help the cause of boosting global growth, reinforcing Obama administration pressure on the nation to avoid weakening the yen.

"At a moment when global growth appears weaker than it should be, and trade flows appear weaker than they should be, any movement that a country would make that would look like it was intended to put them at a competitive advantage versus their peers is one that would not help boost global growth," Wally Adeyemo, White House deputy national security adviser for international economics, said in an interview Wednesday.

As President Barack Obama heads to the Group of Seven leaders meeting starting May 26 in Mie Prefecture, the yen's almost 10 percent surge this year is squeezing the world's third-largest economy, spurring speculation that Japan may intervene in foreign-exchange markets for the first time since 2011.