FILE - In this Jan. 30, 2010, file photo, Vice President Joe Biden, left, with his son Hunter, right, at the Duke Georgetown NCAA college basketball game in Washington. Since the early days of the United States, leading politicians have had to contend with awkward problems posed by their family members. Joe Biden is the latest prominent politician to navigate this tricky terrain. (AP Photo/Nick Wass, File)

NEW YORK (AP) — Facing intense scrutiny from President Donald Trump and his Republican allies, Hunter Biden says he will step down from the board of directors of a Chinese-backed private equity firm at the end of the month as part of a pledge not to work on behalf of any foreign-owned companies should his father win the presidency.

Biden, the 49-year-old son of Democratic presidential candidate Joe Biden, revealed his plan Sunday in an internet post written by his attorney, George Mesires, who outlined a defense of the younger Biden’s work in Ukraine and China, which has emerged as one of Trump’s chief lines of attack against Hunter’s father despite no proof of impropriety.

“Hunter makes the following commitment: Under a Biden Administration, Hunter will readily comply with any and all guidelines or standards a President Biden may issue to address purported conflicts of interest, or the appearance of such conflicts, including any restrictions related to overseas business interests. In any event, Hunter will agree not to serve on boards of, or work on behalf of, foreign owned companies,” Mesires wrote.

He continued: “He will continue to keep his father personally uninvolved in his business affairs, while availing himself as necessary and appropriate to the Office of the White House Counsel to help inform his application of the Biden Administration’s guidelines or standards to his business decision-making.”

Joe Biden, speaking to reporters after a union forum in suburban Des Moines, Iowa, said his son did not discuss that decision with him before posting the statement.

“No one has asserted my son did a single thing wrong,” Biden added, pounding his finger into the podium, “except a lying president.”

And Biden promised to bar his family members from occupying any office within the White House and said they won’t “sit in meetings as if they are a Cabinet member.” That was a jab at Trump, who taps daughter Ivanka and her husband, Jared Kushner, as advisers. Biden did not say if his pledge meant that Jill Biden, his wife, would not get the office traditionally assigned to first ladies, should he win.

He further vowed that no one in his family will have “any business relationship with anyone that relates to a foreign corporation or foreign country.”