WASHINGTON (Reuters) - A Democratic U.S. senator on Sunday called on Congress to ban military-style weapons and stop firearm sales to suspected extremists following the largest mass shooting in U.S. history.

"It's time for Congress to finally act on gun violence and ban military-style weapons, put limits on clips and magazine sizes, ban those on the terrorist watchlist from purchasing firearms and require background checks on all gun sales," Senator Bob Casey of Pennsylvania said in a statement.

"We know that the shooter in Orlando used a high-powered weapon that allowed him to fire a large number of bullets in rapid succession," he said.

(Reporting by David Morgan; Editing by Meredith Mazzilli)