President Trump’s slow, unenthusiastic and — yes — mean response to the humanitarian crisis facing Puerto Rico in the aftermath of Hurricane Maria is astonishing. He seems oblivious to the fact that the 3.4 million people living there are Americans, in many cases more patriotic than he is.

First, let’s talk about Trump’s delayed response to the disaster. While Trump visited Texas twice within a week shortly after Hurricane hit that state, and traveled to Florida five days after Hurricane Irma, he made no immediate plans to visit Puerto Rico.

Facing a barrage of criticism in the media and tweets from — among others — former Democratic candidate Hillary Clinton for ignoring the natural disaster in Puerto Rico, the White House announced Tuesday that Trump would visit the island on Oct. 3. It will be almost two weeks after the storm.

But that’s a minor detail compared to the lack of interest Trump showed in the days that followed Hurricane Maria’s Sept. 20 passage through Puerto Rico.

In the five days that followed, after the hurricane had left the entire island without electricity and half of it without water, Trump wrote only one tweet about Puerto Rico’s tragedy — a message to the island’s governor, Ricardo Rossello, saying, “We are with you.” By comparison, during the same period Trump wrote 17 tweets related to his claim that NFL athletes who kneel during the national anthem disrespect the flag.

There are legitimate reasons to wonder whether Trump has any credentials to give NFL players lessons about patriotism. “A great way to show respect for the flag is to refuse offers of clandestine election assistance from hostile foreign espionage agencies,” wrote The Atlantic magazine editor David Frum, referring to Trump’s cozy ties with Russia during the campaign.

More to the point, it was utterly insensitive to start a debate over respect to the flag in the middle of the Puerto Rico tragedy. After several days of Trump’s silence on Puerto Rico, singer Marc Anthony — whose parents are Puerto Rican — tweeted on Sept. 25, “Mr. President shut the [expletive] up about NFL. Do something about our people in need in Puerto Rico. We are American citizens too.”

When Trump finally reacted to the avalanche of criticism, he did it with a tweet that sounded mean, if not cruel. Trump said in a tweet that Puerto Rico is in “deep trouble” after Hurricane Maria, and that its billions of dollars in debts to Wall Street banks “must be dealt with.”

Puerto Rico is bankrupt, and it must reach a deal with Wall Street banks to get back on its feet. But Trump’s tweet was the equivalent of lecturing a patient who is rushed into the emergency room in critical condition about the need to eat healthier and exercise.

“It is inconceivable that at a time like this, when hospitals in Puerto Rico don’t have electricity, half of the island is without water, and people’s lives are endangered by the threat of epidemics, that the president is worrying about Wall Street’s interests,” says Edwin Melendez, director of the center for Puerto Rican Studies at Hunter College in New York.

Melendez told me that he has not been able to talk with his son and grandson on the island since the hurricane hit almost a week ago. He learned only that they are safe after speaking to a relative with access to a satellite phone.

At the very least, Trump should use his executive power to send more army engineers to the island. Puerto Rico needs boots on the ground to restore water and electricity services, and to rebuild roads and bridges.

In addition, Trump should exempt Puerto Rico from a FEMA regulation that requires local governments to pay 25 percent matching funds for certain types of emergency assistance. Puerto Rico’s economy is totally paralyzed. It can’t pay, even if it wanted to.

Finally, Trump should waive the so called Jones Act, a U.S. protectionist measure from the 1920s that requires that only American ships carry goods from one U.S. port to another. It is now preventing foreign ships coming from the U.S. mainland from bringing relief supplies to the island.

Above all, Trump must understand that — whether he likes them or not — Puerto Ricans are American citizens. More than 200,000 Puerto Ricans have served in the U.S. armed forces since 1917, including 48,000 during the Vietnam War (the same war that Trump avoided serving in by requesting several draft deferments.) They deserve better treatment.

Andres Oppenheimer is a comlumnist for Tribune Media Services.