Former vice president Joe Biden Photo: VCG

Democratic presidential hopeful Joe Biden says his family members would not engage in any business abroad if he were to win the White House next year, citing the activities of Donald Trump's children as problematic.

But the former vice president defended his son Hunter's work on the board of a Ukrainian gas company, which has become a focus for Republicans in the impeachment probe swirling around Trump.

"They will not be engaged in any foreign business because of what's happened in this administration," Biden said in an interview with "Axios on HBO" that aired Sunday.

"No one's going to be seeking patents for things from China. No one's going to be engaged in that kind of thing,"  he said. "If you want to talk about problems, let's talk about Trump's family."

During Trump's administration, his daughter Ivanka obtained initial approval for a number of trademarks for her fashion label, which has since closed.

The wide-ranging interview was part of a media blitz as the 77-year-old looks to consolidate his position as the frontrunner in the Democratic Party contest to take on Trump in 2020.

Biden was adamant in his defense of his son's work at Burisma, which has been the target of corruption accusations, though Hunter Biden has not been personally accused of criminal wrongdoing.

He admitted, however, he didn't know what Hunter's responsibilities were at Burisma.

Asked whether he wanted to know more, Biden said, "No. Because I trust my son."