National Security Adviser Tom Donilon urged the European Union to designate Hezbollah as a terrorist organization.

In a Feb. 17 oped in The New York Times, Donilon declared that the attack in Bulgaria last July that killed five Israeli tourists and a Bulgarian bus driver — believed to be carried out by Hezbollah — cannot go unpunished.

“Europe can no longer ignore the threat that this group poses to the Continent and to the world,” Donilon wrote.

Emphasizing the urgency of the matter, Donilon said that EU leaders must pursue this designation of Hezbollah in order to “ensure that Burgas is the last successful Hezbollah operation on European soil.”

The Bulgarian Foreign Minister Nikolai Mladenov echoed Donilon’s sentiments regarding the need for action by the EU against Hezbollah.

“We in Europe need to take collective measure to make sure that such attack will never happen again on EU soil,” Mladenov said.

“We must send a strong message… that activities like this are unacceptable.”