Former New York City Mayor Rudy Giuliani joined a chorus of Republicans questioning the timing of Thursday's sudden resignation of CIA chief David Petraeus.

The former GOP presidential contender, in an appearance Friday night on Fox News, said the Petraeus resignation is the latest example of the Obama administration's "suppression" of information.

"Now we're going to have a hearing next week, and the man who knows the facts, David Petraeus - he's the only man who can really tell us what the CIA knew, what they did, why they did it, how they did it - he's not going to testify. This is a very convenient way to get the administration out of a very very difficult situation," Mr. Giuliani said on Greta van Susteren's show.

"But this is inevitable. This is like Watergate. This is all going to come out. It may take a month, it may take five months. But this is all going to come out. And every single new coverup they do just makes it much much worse."

Mr. Giuliani was skeptical about the timing of the resignation, coming just days after the re-election of President Obama to a second term.

"This has to have been suppressed. ... They didn't just find out about this," said the former mayor, now a security consultant.

Gen. Petraeus and other intelligence officials had been scheduled to appear before closed-door sessions of the House and Senate intelligence committees on Thursday to answer questions about the administration's handling of the Sept. 11 terror attack in Benghazi that claimed the lives of four Americans, including J. Christopher Stevens, the U.S. ambassador to Libya.