"We've had an incredible month," Donald Trump said. | Getty Trump: 'I don't know' why my poll numbers are going up

Donald Trump may be gaining on and even leading Hillary Clinton in some state and national polling, but the Republican nominee was at a loss Thursday to articulate why he appears to have gained some momentum in recent weeks.

"We've had an incredible month," Trump said on "Fox & Friends." "There is great enthusiasm."


Co-host Brian Kilmeade asked, "What changed?"

"I don't know. You know I think I've been saying similar things. I talk immigration and illegal immigration. I talk about jobs. A lot of jobs. Maybe that's it because I'm very focused on jobs," Trump said.

He said he also talks "about our very depleted military" and "how we're going to fix it and take care of our vets and Second Amendment.

"And judges, I mean, talking about a lot of subjects," Trump said. "We have a lot of problems. This country has problems, believe me."