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The son of former US Vice-President Joe Biden has defended his foreign business dealings amid attacks by the White House and increasing media scrutiny.

Hunter Biden - who has had business ties in Ukraine and China in recent years - told ABC news that he had done "nothing wrong".

But he admitted to "poor judgment", leaving him open to political attacks.

His foreign work - and Donald Trump's intervention - have sparked impeachment proceedings against the president.

Mr Biden's interview with ABC comes ahead of Tuesday evening's Democratic debate, where Joe Biden - a 2020 frontrunner - will square off against 11 other presidential hopefuls.

What did he say?

Breaking his silence on his foreign business dealings, Hunter Biden, 49, dismissed claims of impropriety.

"Did I do anything improper? No, and not in any way. Not in any way whatsoever. I joined a board, I served honourably," Mr Biden said, adding that he did not discuss such business with his father.

But Mr Biden acknowledged the possible political ramifications of his work, saying his failure to do so previously demonstrated "poor judgment".

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"Did I make a mistake? Well, maybe in the grand scheme of things, yeah," he said. "But did I make a mistake based upon some ethical lapse? Absolutely not."

Mr Biden stressed his record on the board of the UN World Food Programme and work for US corporations to defend his lucrative role as a board member for a Ukrainian gas company.

"I think that I had as much knowledge as anybody else that was on the board, if not more," Mr Biden said.

But he acknowledged the appointment may have resulted from his father's clout.

"I don't think that there's a lot of things that would have happened in my life if my last name wasn't Biden," he said.

What's the controversy about?

Mr Biden's foreign business ventures have pulled him to the epicentre of the ongoing impeachment inquiry into Mr Trump.

Media playback is unsupported on your device Media caption What we know about Biden-Ukraine corruption claims

The president and his allies have claimed that as vice-president the elder Biden encouraged the firing of Ukraine's top prosecutor because the prosecutor was investigating Burisma, a gas company that employed Hunter Biden.

These allegations - though widely discredited - were raised by Mr Trump in a 25 July phone call with Ukrainian President Volodymyr Zelensky.

This call has fuelled the Democratic-led impeachment investigation. The inquiry is trying to establish whether Mr Trump withheld nearly $400m (£327m) in aid to nudge Mr Zelensky into launching an inquiry into the Bidens.

Mr Trump has continued to seize on Mr Biden's dealings in Ukraine and China to stage political attacks against Mr Biden and his father, charging both Bidens with corruption, without offering specific evidence.

In Tuesday's interview, Mr Biden dismissed the president's claims as a "ridiculous conspiracy idea".

Last week, Hunter Biden announced he would step down from the board of BHR (Shanghai) Equity Investment Fund Management Company.

His lawyer, George Mesires, told US media his client had not acquired an equity interest in the fund until 2017, after his father had left office.

Mr Biden said last week that he would not work for any foreign-owned companies if his father is elected president.

What's the status of the impeachment inquiry?

Mr Trump is accused by Democrats of breaking the law by pressuring his Ukrainian counterpart to dig up damaging information on Mr Biden on a July call.

The call occurred days after Mr Trump blocked about $391m (£316m) in military aid to Ukraine. Democrats argue this aid was used as a bargaining chip to pressure the new government in Kyiv, a claim Mr Trump has denied.

In recent weeks the US president has also faced charges that he used his personal lawyer, Rudy Giuliani, to pursue personal interests through political backchannels.

On Tuesday Mr Giuliani said he would not comply with a subpoena to appear before the impeachment inquiry.

Democratic debate

Hunter Biden's interview comes hours before his father appears in Westerville, Ohio for his fourth Democratic debate.

Mr Biden will be centre stage as one of 12 hopefuls on Tuesday night, making it the biggest presidential primary debate in US history.

Image copyright Win McNamee/Getty Images Image caption Mr Sanders, Mr Biden and Ms Warren on stage at the Houston debate in September

The former vice-president joins Senator Elizabeth Warren and Senator Bernie Sanders as one of three leading candidates.

But Mr Biden's campaign has been hit by dogged attacks from the president and his allies, especially those related to his son, who may be subject to discussion in the debate.

Mr Biden's initial lead has narrowed in recent polls, with an 8 October Quinnipiac poll finding Ms Warren had overtaken Mr Biden among Democratic voters.

The debate will also mark the return of Mr Sanders to the campaign trail. He suspended his campaign after suffering a minor heart attack in early October.