Democratic presidential candidate Pete Buttigieg on Sunday called out President Trump as a "walking conflict of interest."

The South Bend, Ind. mayor told Jake Tapper on CNN's "State of the Union" that news that former Vice President Joe Biden's son, Hunter, has stepped down from the board of a Chinese firm and is vowing to do no foreign work if his father is elected president in 2020 shows a "difference in standards" between the Bidens and Trump's family.

"Here you have Hunter Biden stepping down from a position in order to make sure even though there's been no accusation of wrongdoing, doing something just to make sure there's not even the appearance of conflict of interest," Buttigieg said.

"While in the White House, the president of the United States is a walking conflict of interest," he added.

He claimed the president's relatives use Trump's presidency to benefit their interactions with foreign governments and that his sons, in particular, pretend "the fact that their father is the president of the United States has no impact on the international business dealings that they do."

"It is a radically different standard, and we cannot allow this president to change the subject especially with unfounded allegations," he said.