Former CIA Director Michael Hayden defended the Obama administration's travel alert cautioning about terrorist activity in Europe, saying the White House acted on "a moral responsibility to let your citizenry know" about potential threats.

"I think the administration handled this well," Hayden said Sunday on CNN's "State of the Union," a week after the State Department issued the alert. "They put the alert out. They let folks know that there was something different. But they also tried to simultaneously calm fears, tell people they shouldn't cancel travel to Europe.

"Frankly, it's an imperfect science. It's — that's about the best you can do, in term of letting the people know how the danger has changed," he said.

When asked to grade President Obama on how he's doing in combating terrorism, Hayden, who was appointed by President George W. Bush but continued to serve until February 2009, refused to issue a grade, but did say that there are some things he has disagreed with.

"But, by and large, there's been a powerful continuity between the 43rd and the 44th president, and I think that simply reflects the reality that both President Obama and President Bush faced in terms of the threat and the tools that are available to them," he said.

Hayden commended the administration for its "sober and somber" report on Pakistan just presented to Congress, which was "very candid in its assessment of what Pakistan is and is not doing."

"And it attributed it not just to Pakistani capacity, which is always stretched, but also to Pakistani policy and willingness," Hayden said. "I think that, kind of, laid down a challenge to the government in Islamabad that we expect them to do more."