Elizabeth Warren appeared discombobulated when asked if her ethics plan would include prohibiting her vice president for allowing their children to serve on the board of a foreign business.

'No,' she definitely answered, at first, shaking her head – but she quickly contradicted her answer when a CBS News reporter asked her, 'Why not?'.

'I don't know. I mean I'd have to go back and look at the details on the plan,' the 2020 candidate and Massachusetts senator stumbled over her words as walked back on her initial answer. 'I have to go back and look.'

Usually when asked questions, or when reciting her stump speech, Warren, who either polls as first or second in the crowded primary field, confidently recites: 'I have a plan for that.'

Elizabeth Warren appeared to struggle when a reporter asked if her ethics policy would allow her vice president to sit on the board of a foreign company. 'No... I don't know. I mean I'd have to go back and look at the details on the plan,' she said while shaking her head and stumbling over her words

The flustered answer was uncharacteristic of the top-tier candidate whose usual response to a policy question is, 'I have a plan for that'

FLAG: Senator Elizabeth Warren appears uncharacteristically flustered when asked if her ethics plan would allow her Vice President's son to serve on the board of a foreign company: "No," she said. "I don't know. I mean I’d have to go back and look at the details." #nhpolitics pic.twitter.com/EksLlMEsew — Nicole Sganga (@NicoleSganga) September 25, 2019

The phrase has become a call sign for her campaign and audience members even say it in tandem with the progressive candidate when she's listing her position on a variety of different issues.

The question comes as controversy has engulfed 2020 candidate and former Vice President Joe Biden over his son Hunter Biden's connections to a Ukrainian natural gas firm Burisma Holdings.

Revelations of Hunter's former position as a board member of Burisma emerged after a whistle-blower alleged that Donald Trump pressure Ukrainian President Volodymyr Zelesnky to probe the Biden's business dealings there.

Trump insisted that his conversation was centered around keeping foreign corruption, including from Biden and the U.S., out of Ukraine.

However, the revelations caused many on-the-fence Democrats to finally call for the president's impeachment and after years of holding back House Speaker Nancy Pelosi announced Tuesday that the House was launching an impeachment inquiry into the president.

But Trump insists that Joe Biden and Hunter should be the ones investigated on this matter, and even released on Wednesday an unredacted transcript of the July 25 phone call with Zelensky.

Her contradictory answer comes as Joe Biden and his son Hunter Biden's (left) involvement in a Ukrainian natural gas firm is under scrutiny

In 2014, while Biden was still serving as Obama's vice president, Hunter was hired by the Ukrainian natural gas firm as a board member. Hunter reportedly made $50,000 a month in that post, but he stepped down from the company earlier this year.

Burisma Holdings had ties to then-Ukrainian President Viktor Yanukovych, a pro-Russia leader, which raised eyebrows in Washington. But at the time, the White House insisted that since the vice president's son was a private citizen, there was no conflict of interest.

Joe also insisted that he never discussed his son's business in the Ukraine, which was contradicted by his son's own account earlier this summer.

In a New Yorker article a few months ago, Hunter recalled a 2015 conversation he had with his father about Burisma: 'Dad said, 'I hope you know what you're doing,' and I said, 'I do.''

The Democratic front-runner said last month that if elected president in 2020, he would completely separate his family's business dealings and his administration to steer clear of any conflicts of interest.

Warren's flustered answer to a question about vice presidential conduct is likely an attempt to not to rock the boat in placing onus on the president for the conversation and not the former vice president for his potential involvement in his son's foreign business dealings.

In the 'End Washington Corruption' plan on her campaign website, Warren says she will stop those serving in Washington from being able to get involved in investing in stocks or having any connections to Wall Street.

'We will also shut the revolving door between Wall Street and Washington and permanently ban Senators and Congressmen from trading stocks in office and from becoming lobbyists when they retire – not for one year or two years, but for life,' her policy plan reads.