Chris Murphy. Zach Gibson/Getty Images Sen. Chris Murphy of Connecticut called for more extensive gun-control laws in the hours after the mass shooting in Las Vegas on Sunday night.

Murphy said in a statement on Monday that his "heart goes out to the victims, their families, the first responders, and the entire Las Vegas community."

"Nowhere but America do horrific large-scale mass shootings happen with this degree of regularity," he said. "Last night's massacre may go down as the deadliest in our nation's history, but already this year there have been more mass shootings than days in the year."

Mass attacks have happened in other countries, such as the terrorist attacks in Paris in November 2015, in which 130 people were killed.

However, the attack on Sunday at the country music festival in Las Vegas, in which at least 59 people were killed and 527 were injured, quickly became the deadliest mass shooting by a sole perpetrator in modern US history, prompting Murphy to call for increased gun-control measures. He did not specify what those measures would entail.

"This must stop," he said. "It is positively infuriating that my colleagues in Congress are so afraid of the gun industry that they pretend there aren't public policy responses to this epidemic. There are, and the thoughts and prayers of politicians are cruelly hollow if they are paired with continued legislative indifference. It's time for Congress to get off its ass and do something."

Murphy has previously pushed for more extensive gun-control laws. Last year, he mounted one of the longest filibusters in history — nearly 15 hours — while pushing for a gun-control vote in the wake of the terrorist attack at the Pulse nightclub in Orlando.

Murphy formerly represented the district containing Newtown, Connecticut, where 20 children and six adults were killed in a 2012 school shooting.