James Woolsey, President Clinton's former CIA director, said he is advising Donald Trump on national security matters because the Republican presidential candidate won't "blab" or "go yakking" about state secrets, and because he thinks Hillary Clinton would spend too much.

Woolsey said during a Monday interview on CNN that Trump "seems willing to keep a secret and not to blab everything to the public and our opponents when he comes up with something about national security that ought to be kept quiet."

"I think that's good," he said. "You can't go yakking about everything you're interested in and you have to keep your counsel."

Woolsey said he is happy that Trump has been "very cautious in setting out details" about defeating ISIS, stating that "I think you don't want to telegraph in advance what you are going to do."

Trump recently talked about a classified intelligence briefing he received during his campaign by saying he left with the impression the briefers disagreed with the Obama administration's policy based on their body language. But Woolsey said he didn't have a problem with that because "I wouldn't suggest body language is classified. I've never heard of it being classified."

When asked if he could think of a particular moment where Clinton told secrets that may have pushed him to supporting Trump, Woolsey said he could not think of a single instance. But he did say he disagreed with her budgetary proposals.

"I think the problem is her budget," he said. "She is spending so much money on domestic programs ... that I think there will be very little room for the changes and improvements in defense and intelligence that I think need to be made."

He added that he doesn't understand the controversy over Trump praise for Russia's President Vladimir Putin. "What matters is not the sort of niceties," he said. "It's what they do, whether they have a strong national security establishment and utilize it wisely. I don't really think saying somebody is a strong leader is a disastrous move at all."

Woolsey had criticized Trump's support for banning Muslims from the United States, but said that the Republican nominee has "modified" his position.

"I think there are legal problems involved, quite possibly First Amendment problems, in banning Muslims but ... it's perfectly reasonable even though it might be very tough, to ban at least temporarily, let's say, people from a particular country where there are a great deal many terrorists being generated," he said.