A Syrian man sits by a fire on a destroyed street in Raqqa on Wednesday, two months after YPG-led Syrian Democratic Forces captured the city from the Islamic State. (Delil Souleiman/AFP/Getty Images)

Nathan A. Sales is ambassador at large and coordinator for counterterrorism at the State Department.

The U.N. Security Council has unanimously approved a tough new resolution to combat the movement of foreign terrorist fighters. This is a major step toward achieving one of President Trump's top priorities — defeating the Islamic State and its affiliates around the world.

Thanks to the Global Coalition to Defeat ISIS , we've rolled back the false "caliphate" in Iraq and Syria. Now our challenge is to stop the group from reconstituting itself elsewhere. As our battlefield victories have mounted, the Islamic State has had to adapt to survive.

Some battle-hardened jihadists are heading home from the war zone or wreaking havoc in other countries. Other attacks are being planned and executed by people inspired by the Islamic State's violent ideology. The new face of the Islamic State has shown itself in attacks on soft targets such as hotels, restaurants, stadiums and other large public venues. We've seen this deadly trend overseas and here at home.

Working with our partners around the globe, and with intervention from Secretary of State Rex Tillerson, we took the lead in crafting a new set of tools to address the evolving terrorist threat. The result is U.N. Security Council Resolution 2396, co-sponsored by 66 countries. It includes a number of critical measures to address returning fighters, as well as self-directed terrorists inspired by the Islamic State, al-Qaeda and similar groups.

First, the resolution requires all U.N. members to collect and use passenger name record data to stop terrorist travel. PNR data is the information you give an airline when you book a ticket. It's a powerful tool for preventing "broken travel," a tactic of using convoluted travel routes to evade detection. Mehdi Nemmouche, who was charged with killing four people at the Jewish Museum in Brussels in 2014, reportedly used "broken travel" to reach Europe undetected, traveling from Syria by way of Asia.

The United States has been using PNR for years, and the European Union has directed its members to adopt their own PNR systems by March. Now other countries will be asked to live up to the same standard. We stand ready to assist any partner who lacks the resources or expertise to meet this obligation.

Member states will also be required to maintain watch lists of known and suspected terrorists, and to collect and use biometrics — fingerprints, photos and so on. These tools will help authorities spot foreign fighters if they attempt to board planes or cross borders. And because we all need to interdict threats before they reach our respective shores, the resolution calls for states to share this information in a way that's consistent with human rights obligations.

The resolution further urges U.N. members to tear down the walls that keep authorities from exchanging counterterrorism data with each other, as the United States did after 9/11. It also calls on states to provide notice when they deport suspected foreign terrorist fighters.

As we saw in the Islamic State in Sinai's downing of Metrojet Flight 9268 in Egypt in 2015, terrorist groups continue to threaten global civil aviation. The resolution therefore calls for stricter aviation security standards, including measures to address insider threats and cargo security.

Our adversaries are constantly evolving, and the United States and our partners must evolve just as quickly. We need to remain constantly vigilant against an al-Qaeda on the rebound and an ever-adaptive Islamic State. Resolution 2396 will help us do exactly that. It will strengthen international cooperation to address returning foreign fighters. And it will expand the toolkit we use to confront an increasingly decentralized terrorist threat.