The White House scrambled to play down concerns on Friday that willingness from China to investigate Joe Biden and his son would lead to progress in resolving the trade war.

Amid a rapidly escalating impeachment storm surrounding US President Donald Trump, his appeal to Beijing on Thursday to look into his political opponent infuriated Democrats, who accused Trump of holding US economic and trade interests hostage for the sake of political gain going into next year's election.

Joe Biden, then the US vice-president, tours Beijing with his son Hunter on December 5, 2013. Photo: EPA-EFE alt=Joe Biden, then the US vice-president, tours Beijing with his son Hunter on December 5, 2013. Photo: EPA-EFE

Before his appeal to the Chinese government, Trump had said that "if they don't do what we want, we have tremendous " tremendous power."

But speaking to reporters a day later outside the White House, Trump insisted that trade negotiations and the matter of the Bidens were entirely separate.

"No, it has nothing to do with it," he said when asked whether he would be more likely to strike a deal with the Chinese if they investigated Biden.

"I'd like to make a trade deal with China, but only if it's a great trade deal for our country," said Trump, later adding that his calls on foreign countries to investigate his political opponent resulted only from concern about corruption and were not motivated by politics.

Trump could not give an example of a time he had called on another country to investigate corruption not related to a political rival of his. "We would have to look," he said.

Without evidence, Trump has accused Joe Biden's son Hunter of acquiring US$1.5 billion from China through business dealings in the country, and he said on Thursday that China was in turn rewarded with a "sweetheart deal" on trade while the elder Biden was US vice-president.

Hunter Biden owns an equity stake in a China-based fund " BHR Partners " that in 2014 aimed to raise US$1.5 billion. Citing his lawyer, The New York Times reported on Thursday that the junior Biden has yet to profit financially from his part-ownership nor has he been paid for sitting on the firm's board of directors.

Regardless of the veracity of Trump's charges against the Bidens, the furore is likely to complicate bilateral relations, already strained by a costly trade war that began in July 2018.

White House chief economic adviser Larry Kudlow speaks in Washington on Friday. Photo: AP alt=White House chief economic adviser Larry Kudlow speaks in Washington on Friday. Photo: AP

Trade negotiations are expected to resume next week in Washington. The stakes are high, with the US on the brink of the holiday season and another increase in tariffs on Chinese goods entering the US set to go into effect on October 15.

Larry Kudlow, a senior White House economic adviser, told Bloomberg earlier on Friday that Trump's calls on China to investigate Hunter Biden's business dealings in China were unlikely to have "much of an impact, if anything, on the China trade talks".

China frequently preaches non-intervention when its own internal affairs become the subject of concern by foreign governments; during the United Nations General Assembly meetings in New York last week foreign minister Wang Yi said that China would "never interfere in the internal affairs of the United States".

"And we trust that the American people are capable of sorting out their own problems," he said.

" Mitt Romney (@MittRomney) October 4, 2019

Democrats appeared unswayed on Friday by the White House's attempts to disentangle the Biden issue from looming trade talks, with Representative Ann Kirkpatrick of Arizona taking to Twitter to call recent revelations "a dark moment for our country".

"We are involved in an ongoing trade war, but the President's biggest priority is calling on China to investigate a political rival," she said.

Outrage has not been limited to the American left, however. On Friday, Senator Mitt Romney of Utah, himself a former presidential candidate, became one of the first Republican lawmakers to publicly condemn Trump's appeal for foreign assistance, calling the requests "wrong and appalling".

Romney said, "When the only American citizen President Trump singles out for China's investigation is his political opponent in the midst of the Democratic nomination process, it strains credulity to suggest that it is anything other than politically motivated."

This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP's Facebook and Twitter pages. Copyright © 2019 South China Morning Post Publishers Ltd. All rights reserved.

Copyright (c) 2019. South China Morning Post Publishers Ltd. All rights reserved.