() Mexican President Claudia Sheinbaum should rethink her opposition to the idea of United States troops operating in her country to fight drug traffickers, a federal official said.

Over the weekend, Sheinbaum said she declined U.S. President Donald Trump’s offer to send in the American military. She said her country is willing to collaborate but that U.S. boots on the ground in Mexico would go too far.

“The territory cannot be violated. Sovereignty cannot be sold. Sovereignty is cherished and defended,” she said, speaking in Spanish, during an appearance Saturday.

Trump confirmed the offer and Sheinbaum’s refusal as he spoke with reporters Sunday, saying, “The president of Mexico is a lovely woman, but she is so afraid of the cartels that she can’t even think straight.”

Ron Vitiello, senior adviser for U.S. Customs and Border Protection, told that the Mexican president should reconsider, given the pervasive hold that cartels have across Mexico.

“Hard-working people in Mexico don’t want the cartels to control things,” he said Sunday. “If she needs that help, she should ask for it. This is a once-in-a-lifetime opportunity.”

“She should lean in,” Vitiello added. “If that includes (U.S.) troops, so be it.”

Since taking office in January, Trump has sent a variety of law enforcement agencies to the southern border to stem illegal immigration and drug smuggling, including deadly fentanyl. The American military has even placed forces on federal land along the border on the U.S. side.