The U.S Environmental Protection Agency announced this week it is likely not going to issue new greenhouse gas emissions limitations for refineries in the country.

The agency had hoped it could have new limitations in place by mid-December, but more research is needed, said agency officials.

EPA expects to need more time to complete work on greenhouse gas pollution standards for oil refineries, and is working with the litigants to develop a new schedule to replace the current date of mid-December for a rule proposal, EPA said in a statement.

The agency is trying to fulfill President Obama's pledge of cutting 17 percent of 2005 level greenhouse gases by 2020, but this delay could set that plan back -- especially if anticipated regulations are indefinitely delayed.

Reuters reported the agency previously delayed a proposal to reduce emissions from power plants, although Lisa Jackson, the agency's administrator, said the power plant regulations would come out sometime next year.