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Mexico added new health checkpoints along its US border this weekend as coronavirus cases surge on both sides of the dividing line.

Officials fear crossings during the July 4 holiday weekend could intensify the spread of COVID-19 — despite a three-month ban on nonessential travel that has been increasingly ignored.

“Whichever side of the border you live on, this is NOT the time to cross to shop, eat, or visit family on the other side,” US Ambassador Christopher Landau tweeted Thursday.

“If US citizens continue to make casual cross-border trips, the restrictions will increase, not decrease,” Landau added.

Health screenings in the Mexican state of Sonora, which shares a border with Arizona, will encompass beaches and towns that are popular with both Mexican and American visitors and shoppers, Gov. Claudia Pavlovich said.

The states of Chihuahua, Coahuila, Nuevo Leon and Tamaulipas — all border Texas — have each registered thousands of confirmed coronavirus cases, as has Baja, California, just south of San Diego.

On Tuesday, a confirmed case of COVID-19 in a sprawling refugee camp in Matamoros, Mexico, raised alarms that asylum seekers seeking hearings in the US could become infected while they wait.