President Donald Trump stood on the White House lawn Thursday and called on China to investigate one of his chief political rivals, former Vice President Joe Biden, potentially offering Beijing crucial leverage as it seeks a favorable conclusion to an economically damaging and divisive trade war with the US.

"China should start an investigation into the Bidens," Trump said as he was leaving the White House for a trip to Florida.

Trump's extraordinary request potentially offers Beijing crucial leverage in upcoming negotiations as it seeks to end the trade war with the US.

It also mirrors his 2016 comments as a presidential candidate when he invited Russia to release the emails of his Democratic opponent Hillary Clinton.

Any trade deal struck with the world's second largest economic power would be subject to immediate scrutiny — and raise questions whether Trump offered Beijing beneficial terms in exchange for dirt on his political rivals.

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President Donald Trump stood on the White House lawn Thursday and called on China to investigate one of his chief political rivals, former Vice President Joe Biden, potentially offering Beijing crucial leverage as it seeks a favorable conclusion to an economically damaging and divisive trade war with the US.

"China should start an investigation into the Bidens," Trump said as he was leaving the White House for a trip to Florida. He was referring to business deals Hunter Biden was involved in that drew substantial investment from Chinese government-owned financial institutions. There is no evidence that the former vice president traded favors with the Chinese government to help his son Hunter Biden's business dealings in the country.

Trump's extraordinary request mirrors his 2016 comments as a presidential candidate when he invited Russia to hack and publicly release the emails of his Democratic opponent Hillary Clinton. And it echoes what he privately said to Ukrainian President Volodymyr Zelensky in a July 25 phone call, pressing him to probe the Bidens on unsubstantiated allegations of corruption in their Ukrainian dealings.

Read more: Trump reportedly promised China's president that he'd stay quiet on Hong Kong protests as long as trade talks progressed

The call eventually led an intelligence officer to file a whistleblower complaint, and spurred Democrats to launch impeachment proceedings against Trump.

The president's remarks came just one week before a Chinese delegation is set to arrive in Washington for trade negotiations. Moreover, any trade deal struck with the world's second largest economic power would be subject to immediate scrutiny — and raise questions about whether Trump offered Beijing beneficial terms in exchange for dirt on his political rivals.

CNN recently reported that Trump raised Biden's political fortunes — as well as those of Sen. Elizabeth Warren — during another June phone call.

Still, Trump maintained he had a range of choices when it came to dealing with Chinese leader Xi Jinping.

"We're going to have a meeting with them, we'll see," Mr. Trump said of the talks on Thursday. "I have a lot of options on China. But if they don't do what we want, we have tremendous power."

Beijing has a lot of new leverage in the grinding trade war.

Trump launched the trade war against China in early 2018, aiming to rectify an economic relationship he believed was damaging and unfair to the United States, particularly on the theft of intellectual property and forced technology transfers. But trade negotiations have stalled this year — and both the US and China have slapped hundreds of billions of dollars worth of tariffs on each other's goods, contributing to a cooling of their economic growth.

Seeking to strike a deal that ends the pain, Chinese government officials could "try to hint at a potential exchange of policy concessions for information, if the information is damaging at all," Victor Shih, a Chinese political economy professor at the University of California San Diego, told Reuters.

To seal a favorable deal, China could publicly open an investigation into the Bidens, or could secretly share information on their China dealings with Trump or his emissaries. They could even fabricate business dealings about the Bidens to damage one of Trump's top rivals.

Given its extensive surveillance capabilities, China would likely already have any compromising information on the Bidens' dealings without needing to publicly open an investigation, according to Mary Lovely, a China expert at the Peterson Institute of International Economics.

Read more: Pelosi says it's 'almost not worth' impeaching Trump, but that the Constitution and democracy 'is worth it'

If the Bidens did something wrong, Lovely told Insider, "and that's a big if, China would already know. I don't think this adds much information for them."

Lovely also said, "What it does add is another brick onto Trump's domestic problems," referring to Trump's public call for China to probe the Bidens. Instead, "the Chinese government is focused on ending the trade war that doesn't undermine Xi's political power."

Impeachment is adding uncertainties to the already volatile trade war.

Trump has little room to maneuver with China, given the US has already levied tariffs on $550 billion worth of Chinese goods, with more set to go into effect Dec. 15 on consumer goods such as laptops, cell phones, and toys. Trump could hike existing tariff rates, but that would lead to even more price increases that would hurt Americans, who are already bearing their cost.

As a result, several of the president's advisers have reportedly urged him to make a deal with China and avoid any escalations that further hit American's wallets.

Yet the impeachment probe and any attempt by Trump to link Biden to a possible deal throws a wrench into how long it will take for the dust to finally settle from the trade war.

Eleanor Olcott, a Chinese policy analyst at the TS Lombard consultancy, told the South China Morning Post: "The impeachment proceedings tie Trump's hands when it comes to his domestic agenda, so his attention will be focused on his foreign policy stance, meaning we are likely entering a period of more volatile trade war news."