Clinton, while fundraising in Tennessee and Georgia, called into a Phoenix radio show
to discuss the state of the Democratic nomination fight and a number of issues that matter in Arizona, the next major state to vote.
"I think we've done a really good job securing the border," Clinton said. "I think that those who say we haven't are not paying attention to what was done the last 15 years under President Bush and President Obama."
The comment widely contrasts with what Republicans have long said about the border.
Republican front-runner Donald Trump has pledged to build a wall along the United States' southern border and has knocked Obama and others for their handling of securing the border with Mexico.
During the interview, Clinton said "immigration from Mexico has dropped considerably, it's just not happening any more."
"I voted to secure the border when I was in the Senate. I think we have accomplished a lot of that work," Clinton said. "Now, I think it is time to turn our attention to comprehensive immigration reform."
Clinton's campaign plans to push Clinton's immigration platform ahead of Tuesday's contest in Arizona, where more than 30% of the population is Latino.
The former secretary of state's campaign this week released an ad in Spanish that features Trump and Maricopa County Sheriff Joe Arpaio, whose immigration enforcement methods have made him controversial.
A narrator says, "There will always be obstacles, but with a friend like Hillary, we keep moving forward."
The ad is running in the Phoenix, Tucson and Yuma television markets.