LONDON -- The United States has missed an opportunity to gain economic leverage over China when it opted to put tariffs on the European Union rather than join forces with it, the Speaker of the House Nancy Pelosi said on Monday.

"I thought one of the biggest opportunities was for the U.S. and the EU to join together -- the biggest market in the world, the two combined -- and use that leverage in negotiations with the Chinese," Pelosi told an audience at the London School of Economics.

"So I wasn't pleased when the President put tariffs on the EU because you kind of started to weaken that strength vis-a-vis China."