Republicans in the U.S. House of Representatives challenged President Barack Obama on Tuesday to get tougher with Islamic State militants and promised to develop legislation quickly to suspend resettlement of Syrians in the United States.

"ISIS showed they are committing an act of war against the West," House Speaker Paul Ryan told reporters after a closed-door meeting of House Republican lawmakers, using a common acronym for the militant group.

Ryan said party leaders had assembled a task force to consider legislation "as quickly as possible" that would suspend at least temporarily Obama's plan to admit 10,000 Syrian refugees to the United States.

"This is a moment where it is better to be safe than sorry. So we think the prudent, the responsible thing is to 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," Ryan said.

Several Republicans said they wanted a vote on such legislation as soon as this week.

The attacks in Paris on Friday which killed 129 people have prompted calls from many U.S. lawmakers, mostly Republicans, to bar all Syrians from entering the country. Immigration, like the threat of terrorism, has been a hot-button issue in the 2016 U.S. presidential election.

In Paris, France's President Francois Hollande told a joint session of parliament "France is at war" after the attacks.

Arguing that the attacks had proven they pose too much of a threat to the United States, a few U.S. lawmakers want to include a provision to block them in a spending bill that must pass by Dec. 11 to prevent a government shutdown.

Several state governors, most Republicans, also vowed on Monday to refuse the resettlement of any Syrians in their states.