President Donald Trump issued another clear warning Tuesday to North Korea over its aggression and defended his criticism of the National Football League for its treatment of the national anthem.

“I don’t think that you can disrespect our country, our flag, our national anthem,” @POTUS says.

During a joint press conference in the Rose Garden with Spanish Prime Minister Mariano Rajoy, a reporter asked Trump about the latest threat from North Korea to shoot down U.S. warplanes in international airspace.

“We are totally prepared for the second option; not a preferred option, but if we take that option, it will be devastating, I can tell you that, devastating,” Trump said. “That’s called the military option. If we have to take it, we will.”

Trump said North Korean dictator Kim Jong Un is “acting very badly.”

The president blamed previous administrations going back two decades for not properly dealing with North Korea’s communist regime.

“The things that [Kim] has said over the last year, and if you look back, the things that he has said to past administrations, North Korea is a situation that should have been handled 25 years ago, 20 years, 15 years, 10 years ago, and five years ago,” Trump said. “It could have been handled much more easily. Yet, in various administrations, many administrations, which left me a mess. But I’ll fix the mess. So, we’ll see what happens with North Korea.”

North Korean Foreign Minister Ri Yong Ho said over the weekend that his country would shoot down American warplanes even if they weren’t in North Korea’s airspace. He also called Trump’s comments about the ability of the U.S. to destroy North Korea “a declaration of war.”

Trump thanked Spain for expelling the North Korean ambassador, touted recent sanctions on companies doing business with the regime, and heaped praise on China for pulling back interactions with its client state.

“I applaud China’s latest action to restrict its trade with North Korea,” Trump said. “In particular, I applaud China for breaking off all banking relationships with North Korea, something people would have thought unthinkable even two months ago.”

A reporter asked whether Trump is preoccupied with the controversy of NFL players kneeling during the national anthem, when he also is responding to a hurricane in Puerto Rico, international problems, and domestic issues in Congress such as health care and tax reform.

“I wasn’t preoccupied with the NFL, I was ashamed of what was taking place because to me it was a very important moment,” Trump said. “I don’t think that you can disrespect our country, our flag, our national anthem.”

The president added:

I’ve heard that before, was I preoccupied? Not at all. I have plenty of time on my hands. All I do is work. To be honest with you, that’s an important function of working. It’s called respect for our country.

Many people have died; many, many people. Many people are still horribly injured. I was at Walter Reed Hospital recently and I saw so many great young people. They were missing legs, they were missing arms and so badly injured. They were fighting for our country. They were fighting for our flag. They were fighting for our national anthem.

For people to disrespect that by kneeling during the playing of our national anthem I think is disgraceful.