President Barack Obama will send "specific language" of an Authorization for the Use of Military Force to Congress "relatively soon," White House press Secretary Josh Earnest told reporters .

“We see ISIL, a brutal vicious death cult that in the name of religion carries out unspeakable acts of barbarism,” he said during a speech at the National Prayer Breakfast in Washington on Thursday.

The US president also criticized the terror network for “claiming the mantle of religious authority for such actions.”

He suggested that people in the United States should curb their criticism of Islamic ideas.

“And if, in fact, we defend the legal right of a person to insult another’s religion, we’re equally obligated to use our free speech to condemn such insults and stand shoulder-to-shoulder with religious communities,” Obama said.

US officials say Washington is deploying more military equipment into Iraq as part of the strategy to fight the ISIL and to be better positioned in the event of downed planes.

Last week, Obama condemned the beheading of Japanese freelance journalist Kenji Goto by ISIL terrorists.