President Barack Obama is continuing to issue warnings about Donald Trump, but with a tone indicating he's trying to avoid entering the daily political fray. Josh Robin filed the following report.

President Barack Obama wants you to picture Donald Trump with his finger on the proverbial trigger.

"Just listen to what Mr. Trump has to say and make your own judgment with respect to how confident you feel about his ability to manage our nuclear triad," Obama said.

It's clear Obama doesn't feel confident, but he also seems reluctant to broadcast his reservations daily.

"As I recall, I just answered a question about this a couple of days ago, and I think I made myself pretty clear," Obama said.

On Tuesday, Obama said, "I think the Republican nominee is unfit to serve as president,"

Trump was in Maine.

"We have a president who is incompetent," he said.

His stump speech included expected slams at Obama, the press and his opponent, Hillary Clinton.

"She lies. Boy, does she lie," Trump said.

But Trump included a claim that doesn't withstand fact-checking. It has to do with word that in Janaury the U.S. paid Iran $400 million as four U.S. hostages were released. Obama says it wasn't ransom, rather resolving a decades-old arms deal.

"A tape was made, right? You saw that, with the airplane coming in - nice plane - and the airplane coming in, and the money coming off, I guess, right? That was given to us, has to be, by the Iranians. And you know why the tape was given to us? Because they want to embarass our country," Trump said.

There is no evidence Iranian agents shot and disseminated any footage, which actually shows the Americans being transferred. A Trump spokeswoman didn't get back to us.

Following tradition, both Trump and Clinton will be receiving confidential intelligence briefings, notwithstanding the concern among some that neither is trustworthy.

Clinton stumped in Las Vegas, repeating similar charges against the Republican.

"Donald Trump is not qualified to be president, and he is tempermentally unfit to be commander-in-chief," she said.

Protesters interrupted her speech. They were pressing for animal rights.

Security booted demonstrators from Trump's event who held up copies of the Constitution, apparently inspired by the father of a U.S. solider killed in Iraq, with whom Trump feuded recently.