A lawyer for Kushner said he plans to divest himself of all foreign assets along with his interests in a venture capital firm and an office building in New York. He will also resign as chief executive of Kushner companies and as the publisher of the New York Observer before beginning work in the White House.
Six members of Congress wrote a letter to Attorney General Loretta Lynch and the
U.S. Office of Government Ethics pointing to a 1967 law that says a public official cannot appoint a family member to the same agency in which the official serves.
Kushner lawyer Jamie Gorelick said the rule does not apply to the president because the White House does not fall under the definition of an agency.
The lawmakers also say in their letter that Gorelick's statement that Kushner would recuse himself from matters involving his remaining financial interests after leaving his companies implies that he would still have assets that could be affected by government policy he helps shape.
Trump transition team officials said Kushner's role will involve working on trade and the Middle East, and that he will work closely with Chief of Staff Reince Priebus and Chief Strategist Stephen Bannon.
Unlike members of Trump's Cabinet, Kushner's position does not require Senate approval.
The 35-year-old is married to Trump's daughter Ivanka.
Reporters asked Trump about Kushner's possible role on Monday, to which the president-elect said, "We'll talk about that Wednesday." That is when the president-elect is due to hold a highly anticipated news conference, his first since being elected on November 8.
Trump's inauguration will take place January 20.