López Obrador blamed rich countries for "hoarding" vaccines, calling that "totally unfair," and said "the U.N. has to intervene."
López Obrador has demanded the United States vaccinate the millions of Mexicans living in the U.S. with or without legal documents; Mexico says its consulates in the United States have even been registered as vaccination centers.
But a photo circulated on social media showed a sign posted last week outside one Mexico City vaccination center stating "No Foreigners Will be Vaccinated."
Presidential spokesman Jesús Ramírez said that was a mistake, and promised everyone over 60, foreigners and Mexicans alike, would have access to vaccines.
"That was a photo of one center, and that message was corrected," Ramírez said.
But Dr. Ruy López Ridaura, the country's director of disease prevention and control, said the exclusion of foreigners apparently occurred at other sites in the opening weeks of the vaccination effort.
"There may have been some confusion at some operating sites," López Ridaura said. "It was a communication problem. ... The orders are totally clear now, foreigners will also receive their vaccinations."
López Obrador invited Argentine President Alberto Fernández onstage at his daily morning press conference Tuesday, and the Argentine leader proposed that vaccine companies be forced to cede intellectual property rights and allow anyone to manufacture their shots.
"The idea is to propose at the G20 the need to declare COVID-19 vaccines as 'global goods,' so that they cede their intellectual property rights and all countries can freely produce them," Fernández said.
Mexico is trying to beef up its supply of Pfizer vaccines with Russian and Chinese shots, and late Monday the country received its first shipment of 200,000 doses of the Russian Sputnik V vaccines.
Mexico has had over 2 million test-confirmed coronavirus cases, but the low level of testing means the real number is probably several times that amount.