The US secretary of state has stepped away from dealing with issues related to the controversial Keystone pipeline, because he used to run an oil company.
Rex Tillerson, former boss of Exxon Mobil, recused himself from the matter in February, the State Department said.
TransCanada Corp has applied for a permit for the Keystone XL pipeline, the State Department said.
It resubmitted its application in January after President Donald Trump restarted the project.
“He has not worked on that matter at the Department of State, and will play no role in the deliberations or ultimate resolution of TransCanada’s application,” said a State Department letter sent to the environmental group Greenpeace on Thursday.
The State Department declined to say what prompted Mr Tillerson’s decision.
The project entails a planned 1,179-mile (1,897km) pipeline running from the oil sands of Alberta, Canada, to Steele City, Nebraska, where it would join an existing pipe. It could carry 830,000 barrels of oil each day.
In response to the State Department, Greenpeace issued a new statement saying his recusal “might have never been transparent to the public without people flooding the lines of the Office of Government Ethics today”.
“We must keep pushing this administration into the spotlight and demanding that ethics watchdogs hold these individuals accountable and make these decisions regarding rampant conflicts of interest transparent,” it continued.
It remains unclear whether Mr Tillerson still owns stock in ExxonMobil.