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 department letter was in response to a Greenpeace call for the secretary of state to recuse himself from the issue, as his previous employer would benefit from the pipeline’s construction.
Mr Tillerson was sworn in as secretary just a week after the president signed an executive order to move forward with the controversial pipeline’s construction.
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.
But the secretary of state has said he would fully divest from the company by May to comply with federal ethics rules.
In State Department briefings earlier this week, acting spokesman Mark Toner said the secretary was “working with the Office of Government Ethics” on the issue.