Robert Malley, Washington's suspended Special Envoy to Iran, has joined Princeton University's faculty, as questions swirl about the State Department placing him on leave.
In a statement published by the Ivy League university, Mr Malley, a career diplomat, said he would return to government service “in due course”.
“While I am on leave from the State Department, I am extremely grateful for the opportunity to work with the next generation of public servants,” he added.
Mr Malley will join Princeton's School of Public and International Affairs in the autumn.
“Rob Malley’s significant diplomatic experience and interactions with multiple presidential administrations will be of enormous value to our students,” said Amaney Jamal, Princeton's dean.
“I am very happy to welcome him to the school and look forward to his contributions.”
The State Department has remained tight-lipped about Mr Malley's leave, even in closed-door briefings with Congress.
In a recent closed-door briefing requested by House Foreign Affairs Committee chairman Mike McCaul, the department “refused” to give “meaningful” context, a committee official told The National.
The House committee representative added that US President Joe Biden's administration had cited the Privacy Act in its response to questions over Mr Malley's leave.
The Privacy Act “prohibits the disclosure of a record about an individual from a system of records absent the written consent of the individual”, according to the Department of Justice, but has exceptions for disclosure, including to Congress.