Presumed Democratic presidential nominee Hillary Clinton needs to "step up" and explain her use of a personal email address and private server while she was secretary of state, Sen. Dianne Feinstein said Sunday. Former Secretary of State Colin Powell said he also used personal email during his tenure but because the government communications system was antiquated.

Feinstein has fiercely defended Clinton in the past and called on the former secretary of state to be open about the use of a private email account while she served in the Cabinet. "From this point on, the silence is going to hurt her," Feinstein said on "Meet the Press," especially given that Clinton "is the leading candidate ... to be the next president."

Last week, news broke that Hillary Clinton had exclusively used a personal email address via a private server at her family's home in Chappaqua, New York, while she was secretary of state. Using a private email address offered her more control over what eventually becomes public record, and some have accused her of trying to prevent certain messages from becoming part of that record. The State Department is expected to release more than 50,000 pages of Clinton's government-related emails, but not for several months at least. 

In January 2014, Feinstein defended Clinton following political statements made after a Senate report blamed the State Department for not preventing the 2012 attack on the U.S. Consulate in Benghazi, Libya that killed four Americans, including Ambassador Chris Stevens. Republican senators suggested on the Senate floor the report blamed Hillary Clinton, Feinstein said. "The report approved on a bipartisan basis says no such thing," she said in 2014. "Secretary Clinton is not mentioned a single time in the 58-page bipartisan section of our Benghazi report."

Clinton tweeted Wednesday she had asked the State Department to release her emails, and the department would "review them for release as soon as possible." Former President Bill Clinton Saturday told CNN he would not get involved in the controversy and refused to weigh in on whether his wife deserved the scrutiny and criticism over how she managed her email. "I shouldn't be making news on this," he said.

Powell acknowledged he also used a private email account but didn't archive or print out any of his email correspondence and has nothing to turn over to the State Department.

“I don’t have any to turn over. I did not keep a cache of them. I did not print them off. I do not have thousands of pages somewhere in my personal files,” Powell said on ABC's "This Week." “A lot of the emails that came out of my personal account went into the State Department system. They were addressed to State Department employees and [the] domain, but I don’t know if the servers in the State Department captured those or not.“

Powell said he found the government communications system antiquated and started using his personal email to help modernize operations.