WASHINGTON U.S. President Joe Biden's son Hunter Biden on Tuesday offered to testify publicly to a House Republican impeachment inquiry of his father's Democratic administration, a dramatic escalation in a partisan brawl.

In a response to a subpoena from the House Oversight Committee, Hunter Biden's lawyer blasted the panel's probe as "a fishing expedition" and "empty investigation," telling the panel chairman a public inquiry was the only way to prevent "your cloaked, one-sided process."

"We have seen you use closed-door sessions to manipulate, even distort the facts and misinform the public. We therefore propose opening the door," attorney Abbe Lowell wrote committee chairman James Comer in the letter proposing a Dec. 13 public hearing.

Representatives for the committee and Hunter Biden could not be immediately reached for comment on the reports.

(Reporting by Makini Brice and Susan Heavey; Editing by Scott Malone)