Story highlights According to a July 1 salary report on White House personnel, 22 people earned the top salary

"It has been very, very challenging being the only African-American woman in the senior staff," Manigault Newman said

Washington (CNN) Omarosa Manigault Newman, a senior staffer who recently departed the White House and the only African-American drawing a top salary, said Thursday the "lack of diversity" was a challenge she grappled with.

"It has been very, very challenging being the only African-American woman in the senior staff," Manigault Newman told ABC News' "Nightline" on Thursday

As the top communications official at the White House Office of Public Liaison, Manigault Newman was charged with African-American outreach and said she regrets that the administration hasn't reached the level of diversity she "strove to see."

White House press secretary Sarah Sanders on Thursday maintained that despite Manigault Newman's departure they still have a "really diverse team."

Asked how many senior staffers in the White House are African-American now that reality television star has departed, Sanders said: "We have a really diverse team across the board at the White House, we always want to continue to grow the diversity here. We're going to continue to do that."

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