Giuliani, who was mayor of New York when terrorists attacked the World Trade Center on Sept. 11, 2001, and handled the aftermath of the attack, said Sydney had "excellent law enforcement" in place to deal with a potential security threat.
"I can't give you an expert opinion on it," The Australian quoted him as saying. "(But) it seems like your law enforcement and public safety systems here in Sydney ... are first-rate."
Giuliani said the Western world was on the offensive against terror and now had greater capacity to prevent attacks than before the Sept. 11 attacks.
Giuliani was speaking at a press conference, along with U.S. businessman Steve Forbes, to announce the opening of the fifth annual Forbes Global Chief Executives' Conference, which will run from Aug. 30 to Sept. 1 at the Sydney Opera House.