(CNN) Hillary Clinton slammed Donald Trump and issued a strong defense of the Clinton Foundation Wednesday amid the Republican nominee's claims that she used public office for personal gain.

Speaking to CNN's Anderson Cooper in her first national news interview in nearly a month, Clinton pushed back against Trump's accusations and issued perhaps her most succinct answers on her use of a private email server during her time leading the State Department.

"What Trump has said is ridiculous," Clinton said. "My work as secretary of state was not influenced by any outside forces. I made policy decisions based on what I thought was right."

She added: "I know there's a lot of smoke, and there's no fire."

Trump has recently upped his attacks on Clinton and her family's namesake foundation, saying that foreign governments and business leaders gave primarily to get something in return.

"It is impossible to figure out where the Clinton Foundation ends and the State Department begins," Trump said Tuesday night at a rally in Austin, Texas. "The specific crimes committed to carry out that enterprise are too numerous to cover in this speech."

'Unique circumstances'

Clinton's husband, former President Bill Clinton, has laid out some steps the foundation will take if his wife wins. It will only accept donations from US citizens, legal residents and US-based independent foundations, and the 42nd president will step down from the board and stop fundraising.

Asked by Cooper about why she is waiting until a possible presidency to make the changes rather than implement them immediately, Clinton said, "Obviously, there will be some unique circumstances."

"Didn't those unique circumstances exist when you were secretary of state?" Cooper interjected.

"No, no, look -- I know there is a lot of smoke and there is no fire," Clinton replied, before blasting an Associated Press report out this week that said more than half of the private citizens with whom she met while at the State Department donated to the foundation.

"It draws a conclusion and makes a suggestion that my meetings with people like the late, great Elie Wiesel or Melinda Gates or the Nobel Prize winner Muhammad Yunus were somehow due to connections with the foundation instead of their status as highly respected global leaders," Clinton continued. "That is absurd. These are people I would be proud to meet with, as would any secretary of state would have been proud to meet with, to hear about their work and their insights."

Pushback from Powell

Clinton has reportedly told FBI investigators that her use of the private server was inspired by former Secretary of State Colin Powell, who has pushed back against the suggestion , saying, "Her people have been trying to pin it on me."

Cooper asked the Democratic nominee about the disparity in the two former diplomats' claims.

JUST WATCHED Hillary Clinton's many earlier explanations of her email saga Replay More Videos ... MUST WATCH Hillary Clinton's many earlier explanations of her email saga 02:47

"I am not going to relitigate in public my private conversation with him," Clinton replied. "I have been asked many, many questions in the past year about emails and what I have learned is that when I try to explain what happened, it can sound like I am trying to excuse what I did. And there are no excuses. I want people to know that the decision to have a single email account was mine. I take responsibly for it. I apologize for it. I would certainly do differently if I could."

She added, "I believe the public will be and is considering my full record and experience as they consider their choice for president."

Clinton's faced some criticism even among Democrats who have criticized her response to email scrutiny. David Axelrod, a former Obama senior adviser and CNN contributor, said jokes Clinton about the issue on ABC's Jimmy Kimmel earlier this week fell flat.

"I think she should not joke about this. She's done this a few times. She seemed flippant about it. Obviously there are concerns about how she handled these emails and all these jokes fall flat and it makes it seem as if she's not taking the issue seriously," Axelrod told CNN's "New Day" on Wednesday.