Sen. Dianne Feinstein (D-Calif.) said Hillary Clinton's silence on the controversy over her e-mail use is likely to "hurt her" going forward. (Joshua Roberts/Reuters)

Sen. Dianne Feinstein (D-Calif.) called Sunday on Hillary Clinton to "step up and come out" to explain in more detail why she used a personal e-mail account to conduct government business during her time as secretary of state.

The comments, coming from the top Democrat on the Senate Intelligence Committee, are some of the most forceful that Clinton has faced from a prominent member of her party since questions about her e-mail use flared up last week.

"What I would like is for her to come forward and say just what the situation is, because she is the preeminent political figure right now," Feinstein said on NBC's "Meet the Press." The senator called Clinton the "leading candidate" for president.

Feinstein did not accuse Clinton of any wrongdoing, but she suggested that Clinton "needs to step up and come out and state exactly what the situation is." She added: "I think from this point on the silence is going to hurt her."

Clinton's use of a personal e-mail account was reported last week by the New York Times. Since then, a special House committee investigating the 2012 fatal attack at a U.S. diplomatic compound in Benghazi, Libya, has issued subpoenas for information on her e-mails.

Clinton handed over 55,000 pages of e-mails last year to the State Department after the agency asked her to turn over public records she was holding. They are reviewing her submissions.

Many Republicans have raised questions about whether Clinton's practices complied with government rules and have accused her of being overly secretive. While her surrogates and a spokesman have been defending her actions, Clinton has offered little direct input on the matter.

"I want the public to see my email. I asked State to release them. They said they will review them for release as soon as possible," she tweeted last week.

Feinstein has signed a letter encouraging Clinton to run for president.

In an interview with CBS News published Saturday, President Obama said he learned that Clinton used her personal e-mail for government business "the same time everybody else learned it through news reports."

Obama added, "Let me just say that Hillary Clinton is and has been an outstanding public servant. She was a great secretary of state for me. The policy of my administration is to encourage transparency, which is why my emails — the BlackBerry I carry around — all those records are available and archived, and I'm glad that Hillary’s instructed that those e-mails about official business need to be disclosed."

In an appearance on ABC's "This Week with George Stephanopoulos," former secretary of state Colin Powell said he did not retain any records from the personal e-mail account he used when he was secretary of state.

"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," he said.

Powell declined to opine on what Clinton should do next to address the e-mail controversy.

"That would be inappropriate," he said.

In an interview on CBS's "Face the Nation," Rep. Trey Gowdy (R-S.C.), who chairs the House Select Committee on Benghazi, said, "It's not up to Secretary Clinton to decide what's a public record and what is not."

Rep. Adam Schiff (D-Calif.), who also sits on the Select Committee on Benghazi, defended Clinton and said it was "deeply disturbing" to see the committee issue subpoenas, arguing, "We have the secretary's e-mails. She provided 55,000 pages of them to the State Department. They provided the 900 pages relative to Benghazi to us."