The US Environmental Protection Agency (EPA) has delayed the announcement of new rules regarding the control of carbon dioxide emissions for coal-fired power plants.

An announcement was expected to be issued on 8 January 2018, a year after it was proposed, The Huffington Post reported.

The EPA decision overrides the deadline set by US President Barack Obama, who had revealed plans in June 2013 to finalise new carbon rules during his second-term plans for climate change.

"This is all about the best policy outcome, and the appropriate policy outcome."

EPA air and radiation unit acting administrator Janet McCabe was quoted by The Huffington Post as saying: "This is all about the best policy outcome, and the appropriate policy outcome.

"That is what we are talking about here, and that is why we think it is important to finalise these rules in the same time frame."

The regulations, which are to be announced later in the year, will be the first ever in the US. They will ensure that all new coal power plants preserve a portion of their coal reserves underground.

However, the agency has admitted that the rules will have minimal impact on greenhouse gases, as only a small number of new coal-fired power plants are expected to be developed.

US states can frame their individual regulations, based on the EPA proposals. Those that do not comply are likely to face federal actions, the agency added.

Multiple states have already registered complaints over the EPA regulations, The Huffington Post reported.