The Trump administration on Thursday will roll back regulations aimed at reducing emissions of the potent greenhouse gas methane from oil and gas operations, its latest move to unwind environmental rules ahead of November's presidential election.

During a visit to election swing state Pennsylvania, US Environmental Protection Agency Administrator Andrew Wheeler will formally rescind 2016 Obama administration limits on oil and gas industry emissions of methane, a move criticized by environmentalists when initially proposed last August.

The EPA is expected to retain some of the rules issued in 2012 that control methane emissions and also limit those of so-called volatile organic compounds (VOCs) that cause smog.

But it is also expected to remove sources of emissions, including the transport and storage of oil and gas, from regulation as well as requirements for companies to install equipment to detect methane leaks, according to a source familiar with matter.

It would also prevent any future regulation of methane from facilities built before 2015.

Congressman Guy Reschenthaler, a Republican representing a district at the heart of Pennsylvania's fracking industry, welcomed EPA's decision to "remove burdensome regulations" and "commitment to supporting Pennsylvania gas and oil operators."

The American Petroleum Institute, a powerful fossil fuel lobby, has said it supports the final rule even if some of its larger members like ExxonMobil, BP and Shell have called for mandatory methane regulations. Smaller drillers say the rule is too costly for them to comply with.

"We support this revision," API regulatory affairs director Frank Macchiarola told Reuters. "But we understand that this rule has drawn diverse viewpoints across our industry."

The API said existing VOC regulations have led to methane emissions falling 60% from 2011-2018.

Environmental groups said the move comes as scientific reports highlight the major role methane emissions play in worsening climate change.

"Eliminating these safeguards would ignore the overwhelming body of scientific evidence documenting the urgent need to reduce methane pollution," said Peter Zalzal of the Environmental Defense Fund.

Politics

US EPA to gut methane rules