Today, Secretary of Homeland Security John Kelly announced enhanced security screening measures for all commercial flights to the United States.

Our nation is being targeted daily by terrorists, criminals, hackers, nation states, and more.

But I want to focus my remarks on aviation security and the very real threat we face.

(U.S. Homeland Security Secretary John Kelly announced additional security measures on June 28 for international commercial flights to the U.S. Courtesy of the Washington Post and YouTube)

The world’s first commercial flight took to the skies more than a hundred years ago. It was a simple two-seat plane made of spruce and linen.

And on New Year’s Day 1914, it took a maiden voyage from St. Petersburg to Tampa—flying 64 miles per hour at a low cruising altitude of 50 feet.

It may not sound like much. But a journey that took 20 hours by car now took a mere 20 minutes. Commercial aircraft was a marvel—and the world was never the same.

But history has shown us that with new innovations come new threats.

And just 20 years after that Tampa flight, the world saw its first attack on commercial aviation when a bomb took down a United Airlines flight from Chesterton, Indiana to Chicago.

All on board were killed, and the case was never solved.

Since that time we have continued to be confronted by threats to passenger aircraft.

This isn’t a new issue. But the threat has evolved.

Since 9/11, the United States has seen a series of attempted attacks on commercial aviation. A shoe bomber. Liquid explosives. An underwear bomber.

And a plot to detonate explosive cargo. Most of these were disrupted just in time, but our enemies have not always failed.

In 2015, for instance, ISIS claimed responsibility for the bombing of Metrojet Flight 9268, which killed all 224 people on board, and became the deadliest air disaster in Russia’s history.

(CNN examines different types of explosives that officials believe may have been used to down Metrojet Flight 9268. Courtesy of CNN and YouTube. Posted on Nov 9, 2015)

Terrorists want to bring down aircraft to instill fear, disrupt our economies, and undermine our way of life.

And it works—which is why they still see aviation as a crown jewel target.

The threat has not diminished.

In fact, I am concerned that we are seeing renewed interest on the part of terrorist groups to go after the aviation sector—from bombing aircraft to attacking airports on the ground, as we saw in Brussels and Istanbul.

(Video of passengers trapped inside the Brussels airport and inside the underground transport system in immediate aftermath of two explosions at the airport and one in the metro system. Courtesy of Associated Press and YouTube. Posted on March 22)

However, we are not standing on the sidelines while fanatics hatch new plots.

The U.S. government is focused on deterring, detecting, and disrupting these threats.

That is why in March I made the decision to ban electronic devices larger than a cell phone from the passenger cabins of U.S.-bound commercial flights from ten airports in the Middle East and North Africa.

I made that call based on evaluated intelligence and real concerns we had about terrorist plotting.

Make no mistake: our enemies are constantly working to find new methods for disguising explosives, recruiting insiders, and hijacking aircraft.

I’ve made a point to talk with everyone I can about securing aviation.

I’ve met with our international partners. I’ve met with our industry leaders. I’ve met with other private sector stakeholders.

My conclusion is this: it is time to raise the global baseline of aviation security.

We cannot play international whack-a-mole with each new threat. Instead, we must put in place new measures across the board to keep the traveling public safe and make it harder for terrorists to succeed.

Today, I am announcing a first step toward this goal by requiring new security measures to be applied to all commercial flights coming into the United States.

These measures will be both seen and unseen, and they will be phased in over time.

They will include enhanced screening of electronic devices, more thorough passenger vetting, and new measures designed to mitigate the potential threat of insider attacks.

We will also lay out a clear path to encourage airlines and airports to adopt more sophisticated screening approaches, including better use of explosive detection canines and advanced checkpoint screening technology.

Additionally, we will encourage more airports to become Preclearance locations.

This not only enhances security, it also increases convenience by allowing international travelers to go through customs and border security screening before boarding their flights to the United States.

(Learn about the Global Entry program and how it can help you speed through international airports! Courtesy of CBP and YouTube)

With this announcement, we send a clear message that inaction is not an option.

Those who choose not to cooperate or are slow to adopt these measures could be subject to other restrictions—including a ban on electronic devices on their airplanes, or even a suspension of their flights to the United States.

However, we expect all airlines will work with us to keep their aircraft, their crew, and their passengers safe.

I have spent months engaging with our closest allies and foreign partners on this issue, and many of them have expressed strong support for this effort.

While the actions we are announcing today will improve the security of U.S.-bound flights, I am hopeful other nations will follow suit.

Unless we all raise our security standards, terrorists—who see commercial aviation as the greatest takedown—will find and attack the weakest link.

Together, we have the opportunity to raise the baseline on aviation security globally, and we can do it in a manner that will not unduly inconvenience the flying public.

Let me be clear: security is my number one concern. Our enemies are adaptive, and we must be too.

A number of the measures we plan to put in place can be dialed up or down in a risk-based, intelligence-driven manner. And over the next several weeks and months, we’ll work with our partners to ensure these measures are fully implemented.

Again, today is just the starting point. We are taking prudent steps to make aircraft more secure, to reduce insider threats, and to identify suspicious passengers.

In the meantime, we will launch a concerted effort with our foreign partners to put in place wider counterterrorism improvements.

This will include better information sharing, expanded exchanges of terrorist watchlists, and more advanced security checks of travelers around the world.

Finally, let me commend all of the outstanding men and women throughout the Department who make aviation security their daily mission.

Whether they are working on the front lines at the TSA checkpoint, developing better screening technology in the labs, or preparing the intelligence that helps us make tough decisions, every passenger owes them a debt of gratitude.

I am proud to lead them, and all of the DHS employees who make our nation more secure.

I also want to thank our international partners and the airlines I have met with recently.

We have had productive discussions about the threats we face, and I am encouraged by their effort to find solutions that will help elevate global security standards.

Learn more about these aviation security measures and read the Secretary’s full prepared remarks.

– Secretary of Homeland Security John Kelly