Washington, Jan 21 (Reporter) U.S. President Donald Trump Monday declares a national energy emergency in an executive order with an eye on driving down energy costs. As the first of this kind declared by the U.S. federal government, the emergency is expected to enable the federal government to crank up energy production by tapping emergency powers. The United States is the largest producer of both crude oil and natural gas in the world and is also the top exporter of liquified natural gas (LNG) globally...////...