WASHINGTON — President Biden this month made dual moves to reduce greenhouse gas emissions, imposing tougher fuel-efficiency standards on automakers and challenging them to drastically ramp up sales of electric vehicles by 2030.

Biden signed an executive order on Aug. 5 that sets a target for electric vehicles, hydrogen-fuel cell and plug-in hybrid vehicles to make up 50% of U.S. sales by 2030 — a voluntary goal that auto makers said would entail federal support for vehicle charging stations and consumer tax incentives.

Separately, the U.S. Environmental Protection Agency proposed new rules that would require automakers to achieve a fleet-wide average fuel-efficiency equivalent of 52 mpg by the 2026 model year, using an industry measure that takes into account both fuel efficiency and emissions reductions.

The current requirement for that model year is 43.3 mpg under rules set in 2020 by the Trump administration.

Automakers would be allowed some increased flexibility to use credits they banked in past years by surpassing their goals to comply with the rules, the agency said. Auto executives said the targets were largely in line with their expectations.