WASHINGTON - US President Donald Trump Monday declared a national energy emergency in an executive order with an eye on driving down energy costs.

Inadequate energy supply and infrastructure in the country causes and makes worse the high energy prices that devastate Americans, particularly those living on low- and fixed-incomes, said the executive order.

The executive order also cited energy security, foreign policy and technology innovation as part of the consideration to declare a national energy emergency.

The heads of executive departments and agencies were required to identify and use emergency powers to "facilitate the identification, leasing, siting, production, transportation, refining, and generation of domestic energy resources, including, but not limited to, on Federal lands", it said.

Meanwhile, the US Environmental Protection Agency shall consider issuing emergency fuel waivers to allow the year-round sale of E15 gasoline to meet any projected temporary shortfalls in the supply of gasoline across the United States, according to the executive order.

The lengthy document also includes multi-front efforts to speed up deployment of energy infrastructure.

Trump also signed a separate executive order to maximize the development and production of natural resources in Alaska by expediting the permission and lease of energy and natural resources projects and prioritizing development of liquified natural gas (LNG) projects.

As the first of this kind declared by the US 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 as well as the top exporter of LNG globally.