AP Photo/Virginia Mayo

French President Francois Hollande speaks during a media conference at the conclusion of an EU summit in Brussels on Dec. 18. European Union leaders reconvened in Brussels for the final day of their year-end summit with a wide-ranging agenda including how to build greater economic unity among their 28 countries and stepping up the fight against extremism.

BRUSSELS (AP) — Shocked by the bloody Paris attacks, European Union leaders  vowed an “uncompromising fight against terrorism” and called for wide-ranging countermeasures ranging from beefed-up immigration controls to a crackdown on illicit weapons-trafficking.

Leaders of the 28 EU member countries also pledged on Dec. 18, quick action to better restrict violent extremists’ ability to finance their actions, including via the imposition of asset freezes.

The Brussels summit was the first time the EU leaders had assembled since the Nov. 13 attacks, claimed by the Islamic State organization, that killed 130 and wounded hundreds more in Paris.

Those attacks “have only strengthened our resolve to continue our uncompromising fight against terrorism and to make full use of all the tools at our disposal, including close coordination with key partners such as the United States,” EU leaders said in a joint statement.

They also agreed it was crucial to implement systematic and coordinated border checks at European countries’ external frontiers in order to know who is coming and going, and promised to rapidly review proposals by the EU’s executive arm to clamp down on the illegal sale of firearms, especially the models of high-powered semi-automatic weapons used by some of the Paris attackers.

“We face a common threat,” British Prime Minister David Cameron told a post-summit news conference. “No one country can defeat it alone. We have to defeat it together.”

The British leader said that to better neutralize the threat of violent extremist groups like Islamic State, Europe needs more systematic sharing of information, better cooperation in the field of aviation security, coordinated efforts to choke off the targeted groups’ financing and propaganda, and a clampdown on explosives.

At the EU summit, “we got very clear agreement here to take forward all of these proposals,” Cameron said.

Last month’s coordinated attacks on Paris restaurants and cafes, a theater and a suburban soccer stadium highlighted the ready availability in Europe of military assault rifles, as well as gaps in the immigration and customs checks that allow even people subject to international search warrants to travel unhindered.

Twenty-two EU countries belong to the so-called Schengen zone, where no visa is needed to journey between one member nation and another.

Recent history, though, indicates progress in the counterterrorism field can be slow. After the Jan. 7-9 earlier attacks in Paris, a summit called for a strong directive to allow the exchange of data on air passengers. But it may not be until next Februarythat such a system is given final approved by the European Parliament.

“It’s simply not enough to proclaim, to decide_it’s a matter of putting things into effect,” French President Francois Hollande told reporters Friday.

Lorne Cook contributed to this report