House Speaker Paul D. Ryan on Tuesday called for a “pause” in President Obama’s program to admit Syrian refugees into the United States.

“Our nation has always been welcoming, but we cannot let terrorists take advantage of our compassion,” Ryan (R-Wis.) said after emerging from a closed door meeting for House Republicans. Ryan said:

This is a moment where it’s better to be safe than to be sorry. So we think the prudent, the responsible things take a pause in this particular aspect of this refugee program in order to verify that terrorists are not trying to infiltrate the refugee population. In the end, the ultimate solution to this crisis, is a strategy to defeat ISIS. All of this rises above politics. This is not about politics, this is about national security. And so we will invite all of our colleagues, Republicans and Democrats, to work with us quickly to address the urgent nature of this situation.

Ryan also criticized President Obama’s strategy in Syria, in the wake of the deadly Paris attacks that killed over 120 people Friday.

“It’s clear that this was an act of war and that the world needs American leadership. The national defense bill that I will sign later today requires the President to come up with a plan for defeating ISIS, not just containing, but defeating ISIS. A containment plan is not enough, that has failed.”