Joe Biden's son Hunter has announced that he is stepping down from the board of a Chinese-backed private equity company and will stop working for foreign-owned firms if his father is elected president in 2020.
Hunter Biden, 49, has found himself dragged into the spotlight amid attempts to impeach Donald Trump. He was on the board of a Ukrainian gas company which was being investigated by the authorities, and Mr Trump asked Ukraine's president to look for evidence of wrongdoing by Joe Biden. That call - requesting foreign assistance to damage a political rival - sparked the impeachment inquiry.
On Sunday Hunter Biden announced he was leaving his current role on the board of BHR (Shanghai) Equity Investment Fund Management Company, which was set up in 2013 to invest Chinese capital outside China.
George Mesires, Hunter Biden's lawyer, said he will resign at the end of the month from the management company of a private equity fund that's backed by Chinese state-owned entities.
He also reiterated that he never discussed his business activities with his father.
"Hunter always understood that his father would be guided, entirely and unequivocally, by established US policy, regardless of its effects on Hunter's professional interests," the statement said.
"He never anticipated the barrage of false charges against both him and his father by the President of the United States."
Mr Trump and his personal lawyer Rudy Giuliani have repeatedly claimed, without providing evidence, that Hunter Biden made millions of dollars from China while his father was vice president.
They have also made unsubstantiated claims that Joe Biden used his position to help end an investigation in 2016 into the owner of Burisma, one of the country's largest private gas companies, where Hunter Biden sat on the board. Burisma's owner had been under investigation for alleged money laundering and abuse of power. The allegations predated Hunter Biden's joining the board in April 2014. He stepped down earlier this year.
The Bidens firmly deny any wrongdoing.
Earlier this month, Mr Trump raised eyebrows by publicly called on China to investigate the Bidens.
A spokesman for China's foreign ministry rejected that notion, saying it wouldn't interfere in the internal affairs of other countries.
"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," the statement said.
"He will continue to keep his father personally uninvolved in his business affairs."
Hunter Biden's pledge to avoid foreign work if his father wins the White House sets him apart from Mr Trump's children, who have continued working with foreign business partners from Dubai to Indonesia and India while his father sits in the White House.
After Mr Trump won the presidency in 2016, he handed the running of the Trump Organization to his sons, Don Jr. and Eric, and said they wouldn't do any new overseas deals. But they have continued to push the Trump Organization's existing foreign deals, including visits to promote luxury resorts in Indonesia, condo sales in India and an expansion of their golf resort in Scotland.
The Trump sons have joined in on the attacks, accusing Hunter Biden of using his family name for personal gain while his father was vice president.
"At the VERY LEAST, there's an appearance of impropriety," Don Jr. tweeted.
And at a rally in Minneapolis this week, Eric Trump attacked Hunter Biden, whipping up the crowd with chants of "Lock him up," a replay of his father's familiar campaign stump speech targeting Hillary Clinton in 2016.
Joe Biden has defended his son and vowed to make him a visible part of his campaign.
"He's a fine man. He's been through hell," he said.
"I'm also confident the American people know me, and they know my son."