By Echo Wang, Marwa Rashad and Trevor Hunnicutt DAVOS, Switzerland (Reuters) -U.S. President Donald Trump demanded OPEC lower oil prices and the world drop interest rates in a speech to global business and political leaders and warned them they will face tariffs if they make their products anywhere but the U.

The U.S. president used the World Economic Forum to offer the global elite a warning: He intends to follow through on his “America First” campaign promises.