The US President heaped praise on the shamed general who was forced to resign last week after details emerged of his extramarital affair with his biographer Paula Broadwell.
He told reporters he sympathised with the military leader's devastated family, but added that he hoped they could now move on with their lives.
Today, General Petraeus is expected to make his first appearance since he quit as director of the CIA last Friday.
He will give evidence behind closed doors to the Senate Intelligence Committee investigating the deadly attack on the US Consulate in Libya, which killed the ambassador Chris Stevens and three others.
Dianne Feinstein, the Democratic Senator from California, said General Petraeus was "very willing and interested" in talking to the members.
However, the topic of his adultery was the first question at yesterday's White House press conference, despite the looming threat of the "fiscal cliff", a perfect storm of tax and spending cuts tipped to plunge the US back into recession.
"I have no evidence, from what I have seen at this point, that classified information was exposed," said Mr Obama of the illicit relationship between General Petraeus and Ms Broadwell.
The President said he was withholding judgment on the manner in which word of the Petraeus scandal became public. There were questions about why the White House wasn't informed of the lengthy probe until after last Tuesday's election day.
Mr Obama said: "I'm going to wait and see."
The House Intelligence Committee was holding hearings yesterday regarding the handling of the probe and the timing of its release.
The relationship with Ms Broadwell emerged three days after Mr Obama's triumph over Mitt Romney in the presidential race. There was speculation about Ms Broadwell's possible access to his CIA email account.
Ms Broadwell, 40, allegedly began sending jealous emails to Florida socialite Jill Kelley, another attractive, younger woman who was friends with the general.
The scandal has since embroiled General John Allen – who succeeded General Petraeus as commander in Afghanistan – after it emerged he had exchanged thousands of flirtatious emails with Ms Kelley.
General Allen is now being investigated by the FBI, delaying his expected appointment as the head of Nato forces in Europe.
Ms Kelley, the married mother of three, was a volunteer at a Tampa Air Force base. She lost her access to the base as a result of the scandal.