President Trump declines to respond when asked if he's under investigation by Robert Mueller, the special counsel handling the Russia probe. (Reuters)

As the cameras flashed, President Trump said that he and the Panamanian president seated beside him had lots of things to discuss — but he seemed to home in on just one specific thing.

“The Panama Canal is doing quite well. I think we did a good job building it, right — a very good job.” Trump said.

President Juan Carlos Varela interjected: “Yeah, about 100 years ago.”

“But things are going well in Panama,” Trump continued later, hammering home his point.

Within minutes, Twitter had seized on what it deemed the latest Trump gaffe.

Trump just took credit for building the Panama Canal.

Now he's pissed off the ghost of Teddy Roosevelt. — John Fugelsang (@JohnFugelsang) June 19, 2017

Getting tricky: How do I mix in Bowling Green, Frederick Douglass, Andrew Jackson, Panama Canal & Lincoln's GOP status into a tweet? — John Weaver (@JWGOP) June 19, 2017

In response to the Bowling Green Massacre, President Andrew Jackson hired Donald Trump to build the Panama Canal to keep out the Australians — Marie Connor (@thistallawkgirl) June 19, 2017

We did a great job building the Panama Canal. And I'd also like to congratulate Thomas Edison for the incredible work he's doing! — Donald J. Drumpf (@RealDonalDrumpf) June 19, 2017

Did trump just take credit for the Panama Canal? Does he know when it was built? Maybe he thinks Frederick Douglas was the head engineer. — Kevin Lankes (@KevinLankes) June 19, 2017

At least Trump seems to know that the Panama Canal is in Panama. — skip west (@marrynman) June 19, 2017

A brief recap. On Monday, Trump was hosting Varela and his wife, Lorena — a relatively routine meeting of heads of state at the White House. Statements were made. Pictures were taken.

It was my great honor to welcome President @JC_Varela & Mrs. Varela from Panama this afternoon.

➡️https://t.co/V3VBbh0ygV pic.twitter.com/d10LocQYXA — Donald J. Trump (@realDonaldTrump) June 19, 2017

About 103 years before that, the United States completed construction on the Panama Canal, a 50-mile ribbon of water across the Central American nation that connected the Atlantic and Pacific oceans, providing an all-water route for ships traversing the globe.

[Sweden has no idea what Trump meant when he said, ‘You look at what’s happening … in Sweden’]

The United States ceded control of the canal to Panama in 1999. An expanded canal that holds bigger ships opened last year.

It's still too early to tell where Trump's Panama remarks will fit in the pantheon of the president's verbal gaffes.

It would be hard to unseat the “covfefe” incident from last month. Just after midnight May 31, Trump tweeted, “despite the constant negative press covfefe,” and then, apparently, hit send and went to bed.

Who can figure out the true meaning of "covfefe" ??? Enjoy! — Donald J. Trump (@realDonaldTrump) May 31, 2017

Someone deleted the sentence fragment hours later, but not before “covfefe” spread like wildfire. It trended on Twitter and inspired a thousand memes.

Some people just want to see the world #Covfefe pic.twitter.com/icn1plpHfE — Tony Moore (@TonyPixels) May 31, 2017

And the Panama Canal comments haven't inspired the same animosity as Trump's Frederick Douglass remarks on the first day of Black History Month. That's when the Internet was fairly certain that Trump believed Douglass was a person who was still alive. (For the record, he's not.)

“Frederick Douglass is an example of somebody who’s done an amazing job and is getting recognized more and more, I notice,” the president said. He made the statement during a “listening session” with black voters.

President Trump and press secretary Sean Spicer highlighted Frederick Douglass on Feb. 1, the first day of Black History Month. Trump said that Douglass, the former slave, abolitionist, author and vice-presidential candidate, "is an example of somebody who's done an amazing job and is being recognized more and more, I notice." (The Washington Post)

In surprise move @PressSec announces @realDonaldTrump has named Frederick Douglass to National Security Council. pic.twitter.com/rxucceofPZ — FreundschaftPhoto (@FreundschaftP) February 2, 2017

And Trump was lampooned for talking about a terrorist attack in Sweden that never actually happened.

At a Florida rally in February, Trump mentioned several countries that had been attacked by terrorists after taking in refugees.

“We’ve got to keep our country safe,” he said. “You look at what’s happening in Germany. You look at what’s happening last night in Sweden. Sweden, who would believe this?”

Apparently, no one. No attack occurred there.

“The Late Show” host Stephen Colbert even published a video montage, encouraging his viewers to “never fjorget” the people who didn't perish in the Swedish attacks.

Then a video montage flashed images of the Swedes who were not lost: Swedish Fish, Ikea, the pop group Abba — even the Muppet known as the Swedish Chef.

Read more:

Trump implied Frederick Douglass was alive. The abolitionist’s family offered a ‘history lesson.’

A pastor wrote a book about being a better man. Weeks later, he was caught naked, in an affair.

An ex-NFL player claims he inspired a ‘Gears of War’ character — and he wants a cut

Stephen Colbert calls Donald Trump a liar — over and over and over again