MEXICO CITY, Oct 13 (Reuters) - Mexico"s President Andres Manuel Lopez Obrador on Wednesday said the World Health Organization (WHO) should certify COVID-19 vaccines in public use, amid fears some vaccinated Mexicans will not be able to enter the United States. "The WHO must act correctly, without political or ideological tendencies, sticking to the science," Lopez Obrador said at a regular news conference. Lopez Obrador"s comments come after the United States said it would only allow people inoculated by WHO-approved vaccines to enter its borders. Millions of people in Mexico have been vaccinated with Russian and Chinese shots that do not fulfill that criteria. The U.S. on Tuesday said it was reopening its land borders to fully vaccinated travelers. Russia"s Sputnik V as well as China"s CanSino vaccines are yet to receive approval by the WHO.