Mexico on Sunday threatened to take legal action against the United States for failing to protect its citizens after this weekend's mass shooting in the border city of El Paso.

Of the 20 people gunned down at a Walmart adjacent to the Cielo Vista Mall, at least seven were Mexican citizens, and Foreign Minister Marcelo Ebrard promised Mexico City will act.

In a statement, the Foreign Ministry called the attack in El Paso a "terrorist act against innocent Mexicans."

Posición sobre la tragedia en El Paso Texas : pic.twitter.com/gIXuJcQJLy — Marcelo Ebrard C. (@m_ebrard) August 4, 2019

Ebrard called Saturday's shooting an “act of barbarism.”

“The president has instructed me to ensure that Mexico’s indignation translates into ... efficient, prompt, expeditious and forceful legal actions for Mexico to take a role and demand that conditions are established that protect ... Mexicans in the United States,” Ebrard said in a video posted on Twitter.

Ebrard was in El Paso on Monday to meet with the victims and offer support from the Mexican government. The foreign minister said in a translated statement Monday that he offered a message solidarity from the Mexican people to the families.

Mexican officials will be participating in the investigation and trial of the gunman and will consider extraditing the suspect to face charges in Mexico if necessary.

"We consider this to be an act of terror, obviously in U.S. territory, but against Mexican citizens," Ebrard said. "So we will be sharing all the details with authorities."

At least eight of the dead and six of the injured were Mexican citizens, according to the Mexican government. Ebrard condemned racism and xenophobia in his statement, and called El Paso a binational community.

"We are different cultures, but we need to live and respect each other in Mexico and in the United States," the foreign minister said.

El Paso, America's 22nd-largest city with an estimated population of 682,669, is more than 80 percent Hispanic or Latino, according to U.S. census data. El Paso sits just across the Rio Grande from Ciudad Juárez, which has a population of 1.3 million.

The shooter appears to have been targeting Hispanics and authorities are investigating it as a hate crime. A 21-year-old Texas man was in custody.