The first secretary of the Department of Homeland Security issued a warning that the U.S. postal system is not secure enough against terrorists.

Tom Ridge, who was DHS Secretary from 2003-2005, is calling the postal system "a gaping hole in our national security preparedness."

"Every day, almost 1 million packages are shipped into the United States through the U.S. Postal Service from China, Russia and other foreign countries. These packages go generally unchecked for dangerous and illegal content," Ridge wrote in a USA Today op-ed published on Wednesday.

And though the Congress and the federal government have taken steps in years past to secure the postal system, new technologies have created a new gap, and the volume for U.S.-bound foreign packages has only increased.

"While private sector carriers such as FedEx and UPS quickly adopted new technology and conformed to these updated security protocols, foreign postal services as well as the U.S. Postal Service failed to do the same," Ridge explained. "So most foreign packages shipped through the Postal Service into our country remain without essential security data that law enforcement officials need to properly screen packages and keep our communities safe from terrorists as well as drug traffickers contributing to America's opioid epidemic."

Ridge recommended a requirement that foreign senders "provide essential electronic data, otherwise critical security protocols will remain ineffective."

"We need to be forward thinking in how we secure the various transportation modes crossing our borders — whether that is by planes, trains, cargo or mail," he wrote.

Ridge, who chairs the U.S. Chamber of Commerce's National Security Task Force and is senior advisor to Americans for Securing All Packages, urged both President Obama and Congress to take action as soon as possible because "the safety of our country depends on it."