With the U.S.-Mexico border set to reopen to many fully vaccinated travelers next month, Mexico’s president promised Wednesday to ensure easier access to required vaccination certificates.

Mexican health officials acknowledged this week that many people have been unable to access accepted forms of proof of vaccination that will be needed to cross the border into the United States when restrictions are lifted on Nov. 8.

A digital platform for downloading vaccination certificates rolled out in July but has faced numerous problems.

Now, President Andrés Manuel López Obrador is now promising that a solution is in the works.

During a press conference Wednesday, he said efforts to improve the online system are underway, adding that he believes many people in northern border states have been able to access the required documents.

Still, it’s one more concern for those hoping to enter the U.S. after more than 18 months of travel restrictions that have disproportionately affected Mexican citizens. Other questions include whether people vaccinated with Sputnik V and CanSino shots will be able to cross, since those vaccines have not been authorized by the Centers for Disease Control and Prevention or the World Health Organization.

López Obrador has said he is writing a letter urging the World Health Organization to quickly authorize those vaccines.