Ms. Trump already has an office in the West Wing, and she said last week that she would serve as an informal adviser to her father. But that plan prompted criticism from ethics experts, who said it would allow her to avoid some rules and disclosures.

“I have heard the concerns some have with my advising the president in my personal capacity while voluntarily complying with all ethics rules, and I will instead serve as an unpaid employee in the White House office, subject to all of the same rules as other federal employees,” Ms. Trump said in a statement on Wednesday.

“Throughout this process I have been working closely and in good faith with the White House counsel and my personal counsel to address the unprecedented nature of my role,” she said.

Ms. Trump’s title will be special assistant to the president. Her husband, Jared Kushner, has the title of senior adviser.