The president says the shortages were triggered by his administration's decision to temporarily close some of state oil company Pemex's pipelines -- part of his bid to wipe out rampant fuel theft that cost the country an estimated $3 billion in 2017.

But for a politician who campaigned on energy nationalism and a promise of more Mexican refineries to produce more cheap gasoline, the shortages have turned into a public relations debacle.

At his daily press conference, Lopez Obrador -- an anti-establishment leftist who took office last month after a landslide election win -- vowed to keep up his fight against fuel theft and urged Mexicans not to make the shortages worse with panic buying.

“We're going to resist the pressure. I'm asking people to help us. How can you support us? By acting prudently and calmly, without panicking, without listening to alarmist and biased information,” he said.

“There is enough gasoline in the country... We are in the process of returning to normal deliveries.”

That was little comfort for customers like Alfonso Mendoza, a traveling salesman who spent more than four hours waiting to fill up his car after a week of shortages.

He lives in the central city of Guanajuato, where some people spent the night in their cars, queued up outside the limited number of functioning service stations.

“I couldn't go to work today. I have to travel for my job, so it affects me a lot. It's not good, what (the president) is doing,” said Mendoza. “He's trying to catch the thieves, but we're the ones who get screwed.”