The U.S. Environmental Protection Agency during the week of Aug. 16 sent draft proposals to the White House for tough new U.S. rules governing greenhouse gas (GHG) emissions from large trucks and buses, according to Reuters.

The agency has been working with the U.S. Department of Transportation on improved emissions standards after President Obama announced that he wanted new rules to come into effect for medium and heavy-duty trucks between 2014 and 2018.

The White House said at the time that it was confident haulage firms could cut emissions from heavy trucks by about 20 percent using existing technologies.

The White House Office of Management and Budget (OMB) provided no details on the proposed rules, saying only that it has received a draft proposal for "commercial medium- and heavy-duty on-highway vehicles and work truck fuel efficiency standards."

The OMB stated that the rulemaking would set GHG standards that would lead to the introduction of GHG-reducing vehicle and engine technologies.