Travelers flying directly from Mexico to the U.S. should expect longer security wait lines as any electronics larger than smartphones will be subject to additional safety checks, Mexico's civil aviation authority announced late Tuesday.

Following directions from the U.S. Department of Homeland Security, Mexico will implement stricter checks of portable electronic devices starting Wednesday, though no additional information was provided on the reason behind the security change.

Passengers are advised to show up three hours before their flights to ensure enough time to get through the security checks, the General Directorate of Civil Aviation of the Ministry of Communications and Transportation said in a statement.

Secretary of Homeland Security John F. Kelly said on June 28 that, in an effort to "raise the global baseline of aviation security," his department would phase in new security measures for all commercial flights coming into the United States from abroad.

"They will include enhanced screening of electronic devices, more thorough passenger vetting, and new measures designed to mitigate the potential threat of insider attacks," Kelly told the Council for New American Security Conference.