US President Donald Trump has said the impeachment probe against him has been “very hard” on his family.

Speaking in Louisiana, a state he carried in 2016 by 20 percentage points, Mr Trump lashed out at Democratic investigators and what he called a “deranged impeachment witch hunt”.

While arguing it was a political boon for his reelection, he acknowledged for the first time a personal toll from the impeachment process that stands to cloud his legacy.

“I have one problem,” Mr Trump said. “Impeachment to me is a dirty word, it’s been very unfair, very hard on my family.”

The House began public impeachment hearings on Wednesday.

Mr Trump repeated his denials of wrongdoing in his dealings with Ukraine, asserting he had no need to ask that nation to investigate former Vice President Joe Biden and his family.

“We took down Bush, Clinton, Obama, with no experience, but I had you and we won,” Mr Trump said of his 2016 victory. “Think about that and then think about me, ‘gee, let’s get some help from Ukraine in order to beat sleepy Joe Biden.’ I don’t think so.”

He added, “The people of this country aren’t buying it,” claiming polls show a benefit to Republicans as Democrats focus on impeachment.

“We did nothing wrong,” Mr Trump insisted, “and they’re doing nothing.”