U.S. President Donald Trump will visit El Paso, Texas, on Wednesday in the wake of the weekend's mass shootings.

But El Paso Mayor Dee Margo appeared tense as he announced the visit Monday evening, specifying he will welcome the president as his "formal duty."

"This is not a political visit as we had before," Margo said, referring to the February rally Trump held in the border city of 700,000, when the president argued a border wall would make the United States safer.

"He is president of the United States, so in that capacity, I will fulfil my obligations as mayor of El Paso to meet with the president and discuss whatever our needs are in this community and hope that if we are expressing specifics, that we can get him to come through for us."

News of Trump's visit comes as communities in Texas and Ohio reel from two mass shootings in 24 hours over the weekend, which killed 31 people and wounded dozens.

In El Paso, at least seven Mexican nationals were among 22 people shot when a gunman opened fire at a Walmart during the busy back-to-school season on Saturday. Margo described the shooter as a "white supremacist." The shooter is now in custody.

Total number of deceased as of 8-5-2019 is 22. The breakdown of their gender and nationality is below. <a href="https://twitter.com/hashtag/ElPasoShooting?src=hash&ref_src=twsrc%5Etfw">#ElPasoShooting</a> <a href="https://twitter.com/hashtag/ElPasoStrong?src=hash&ref_src=twsrc%5Etfw">#ElPasoStrong</a> <br><br>10 Female<br>12 Male<br><br>13 U.S. Citizens <br><br>7 Mexican<br><br>1 German <br><br>1 Undetermined —@EPPOLICE

Mexican authorities say eight of the victims were Mexican nationals, although the U.S listed seven. Tens of thousands of Mexicans legally cross the border each day to work and shop in El Paso.

And in Dayton, Ohio, officers gunned down a 24-year-man at the doorstep of a bar-turned-hiding place in the middle of a nightclub district shortly after 1 a.m. Sunday. Nine people were killed, including the gunman's sister.

Trump will also visit Dayton later this week.

The attacks came less than a week after a 19-year-old gunman killed three people and injured 13 at the popular Gilroy Garlic Festival in California before dying of a self-inflicted gunshot wound.

The El Paso shooting was being investigated as a possible hate crime as authorities worked to confirm whether a reported racist, anti-immigrant screed posted online shortly beforehand was written by the man arrested.

Mexico's foreign secretary, Marcelo Ebrard, said Monday his government considers the mass shooting to be an act of terrorism against Mexican citizens on U.S. soil. He said Mexico will participate in the investigation and trial of the man suspected of carrying out the attack.

Many life-threatening injuries in El Paso

Though the two attacks staggered a country accustomed to gun violence, the bigger shock may have been that the death toll wasn't worse.

El Paso authorities offered few details about the assault, but police Chief Greg Allen described the scene as "horrific," and said many of the 26 people taken to hospital had life-threatening injuries.

In Dayton, the bloodshed was likely limited by the swift police response. Officers patrolling the area took just 30 seconds to stop the shooting, which unfolded around 1 a.m. on the streets of the downtown Oregon District, Mayor Nan Whaley said.

Video released by police shows Connor Betts, 24, being shot down by officers just steps away from entering a bar filled with hiding patrons.

Dayton police Chief Richard Biehl said if all the magazines in the possession of a gunman who attacked the Dayton nightclub district were full, he would have had a maximum of 250 rounds. Biehl said it not clear whether all were full. He told reporters Monday that at least 41 spent shell casings were from the gunman, who used a .223-calibre weapon.

People march Sunday while holding sunflowers and singing in honour of the El Paso victims. (Lola Gomez/Austin American-Statesman/The Associated Press)

Had police not responded so quickly, "hundreds of people in the Oregon District could be dead today," Whaley said.

Betts's 22-year-old sister, Megan Betts, was among those killed.

Authorities identified the El Paso suspect as Patrick Crusius, 21, from Allen, a Dallas suburb nearly a 10-hour drive from El Paso.

El Paso's police chief said the gun used was legally purchased near the suspect's hometown.



Crusius, who is being held without bond, said in his application for a public defender that he has no income or assets and has been unemployed for five months.

Shooting suspect Connor Betts approaches a nightclub in Dayton, Ohio, early Sunday in a still image from surveillance video released by police in the city. (Dayton Police Department/Handout via Reuters)

President Donald Trump tweeted Monday that Washington "must come together" in the wake of the shootings "to get strong background checks" for gun users, but provided no details on what sort of legislation he would support.

The Democrat-led House has passed a gun control bill that includes fixes to the U.S. firearm background check system, but it has languished in the Republican-controlled Senate.

The National Rifle Association tweeted:

Read <a href="https://twitter.com/NRA?ref_src=twsrc%5Etfw">@NRA</a>'s statement on <a href="https://twitter.com/realDonaldTrump?ref_src=twsrc%5Etfw">@realDonaldTrump</a>'s call to address the root causes of the horrific acts of violence that have occurred in our country. <a href="https://t.co/ooj2gaKX2K">pic.twitter.com/ooj2gaKX2K</a> —@NRA

Trump suggested Monday that a background check bill could be paired with his long-sought effort to toughen the immigration system. He didn't say how.

Later Monday, former president Barack Obama also weighed in, emphasizing the need to hold public officials to account for gun laws.

Beto O'Rourke, a Democratic presidential candidate and former Texas congressman who is from El Paso, appeared shaken after receiving news of the shooting during a candidates' forum in Las Vegas Saturday.

He said he heard early reports that the gunman might have had a military-style weapon, saying we need to "keep that [expletive] on the battlefield. Do not bring it into our communities."

The shootings were the 21st and 22nd mass killings of 2019 in the U.S., according to the AP/USA Today/Northeastern University mass murder database, which tracks homicides where four or more people killed — not including the offender.