A new Transportation Security Administration proposal will include a heightened screening of electronic devices at foreign airports bound for the United States. 

Security screeners at foreign airports may ask passengers to turn on their electronic devices to ensure that they aren't explosives.

The TSA said Sunday that passengers will no longer be allowed to board planes with devices that do not have power. If a passenger has an electronic device without power, they will be forced to undergo more screening. 

The new measure is part of a security initiative to stave off new threats from terrorists in the Middle East and Europe, according to CNN. 

Secretary of Homeland Security Jeh Johnson told the TSA last week to enhance security at overseas airports that offer direct flights to the U.S. The details of the new measures were not immediately released, and it is not yet known what other measures the TSA will implement for national security purposes. 

The TSA will have to coordinate with foreign governments to implement the new measures at foreign airports, along with intercontinental airlines and security companies. 

"Our job is to ... try to anticipate the next attack, not simply react to the last one. And so we continually evaluate the world situation, and we know that there remains a terrorist threat to the United States, and aviation security is a large part of that," Johnson said on NBC's "Meet The Press," according to CNN. 

"This is not something to overreact to or over-speculate about," he added. 

The new changes will be implemented mainly in airports in Europe and the Middle East. 

While there will not be any changes to what passengers can take aboard flights, passengers will see an increased inspection of electronics, in addition to shoes. There will also be more scanners to detect small amounts of explosives, as well as additional screening at boarding gates in certain cases. 

Johnson said that security measures will only apply to overseas airports, and that the changes will not occur at domestic airports in the near future. 

"I believe that we've taken the appropriate measures to deal with the existing situation and not unnecessarily burden the traveling public," Johnson told NBC.

The new initiatives are being implemented based on intelligence about terrorist groups trying to build new explosives that are harder to trace. 

Although the U.S. did not receive any specific threat that facilitated the new proposals, U.S. officials are worried about the Islamic State of Iraq and Syria (ISIS) building explosives that can pass through security measures without being detected. 

U.S. security officials have focused on thwarting plastic explosives and other explosives that can be hidden in baggage, signaling a change from post-9/11 measures, which included hardening cockpit doors. 

A spokesman for the U.K. Department for Transport also said Wednesday that it is increasing some security measures at airports. 

"For obvious reasons we will not be commenting in detail on those changes. The majority of passengers should not experience significant disruption," a spokesman told CNN. 

"The UK has some of the most robust aviation security measures, and we will continue to take all the steps necessary to ensure that public safety is maintained," they said.