Washington - The White House said on Monday it would be "premature" to reopen the US debate on tighter gun controls in the wake of the mass shooting that left 58 people dead in Las Vegas. "There are time and place for a political debate, but now is the time to unite as a country," Press Secretary Sarah Sanders told the daily White House briefing."A motive is yet to be determined and it would be premature for us to discuss policy when we don't fully know all of the facts or what took place last night." Gaga urges gun controlLady Gaga urged US leaders on Monday to act quickly to tighten gun laws following the carnage in Las Vegas as artists voiced shock at the deadliest shooting in modern US history. While most artists left their comments to general messages of sympathy after the assault on a country music festival, Gaga used her social media power to press politicians. "This is terrorism, plain and simple. Terror bares no race, gender or religion. Democrats and Republicans please unite now," the pop star wrote to her more than 71 million followers on Twitter, where her account is the seventh most popular. She took to task the call for prayers by House Speaker Paul Ryan, who like President Donald Trump and most other Republican leaders is a staunch opponent of regulations on guns. "Prayers are important, but @SpeakerRyan @realDonaldTrump, blood is on the hands of those who have power to legislate. #GunControl act quickly," she wrote.Gaga also invited fans to join her in a live-streamed 20 minutes of silent meditation or prayer "to connect us all through inner peace".Also read: No reports of South Africans killed or injured in Las Vegas shooting - Dirco'Helplessness and sorrow'Country turned pop superstar Taylor Swift, the fourth most followed person on Twitter, steered clear of politics, as she wrote: "There are no words to express the helplessness and sorrow my broken heart feels for the victims in Vegas and their families." Rihanna similarly tweeted: "Saying a prayer for all the victims and their loved ones, also for the residents and visitors of Las Vegas! This was a horrific act of terror!!" At least 58 people were killed and more than 500 injured when a heavily armed gunman opened fire from his hotel room onto an open-air country music festival on the Las Vegas Strip. Jason Aldean, who was playing the headlining set when bullets began raining down, called the attack "beyond horrific"."It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night," he wrote on Instagram. Maren Morris, who played the same Route 91 Harvest festival on Saturday, recalled that "we were all singing" the day before the tragedy. "I'm in shock over this. Heartbroken for all those lives taken too soon," she tweeted. 'I'm okay'Former British women's tennis number one Laura Robson was among those at the concert.The Australian-born British left-hander, ranked 249th in the world and coming off a loss at an event in California on Friday, tweeted that she and a friend were in the crowd when gunfire began. "I'm okay," she tweeted. "We were right there... sounded like fireworks at first then everyone started running. Scary shit. "My friend who was deeper in crowd has been helping people who were shot. We're all in shock." Sports stars from Las Vegas and across the United States were stunned and saddened at the tragedy. "Sad day. Love and prayers #lasvegas. Let's not let hate win. Be kind to one another," wrote former heavyweight boxing champion Mike Tyson, who lives in Las Vegas. "Speechless, pray for my home," US 2016 Olympics high jumper Vashti Cunningham wrote on Twitter. "The pride of Vegas runs deep when you are born and raised in such a great town. I can't fathom the horrific event that has taken place!" tweeted Washington Nationals outfielder Bryce Harper. "My thoughts and prayers go out to the families that have been affected by this and to all the people that have lost their lives way too soon! Las Vegas I love you and stand with you." 'Horrific situation'Tennessee Titans running back DeMarco Murray was a three-sport high school star in Las Vegas and stunned by the incident following his club's 57-14 NFL loss at Houston. "Terrible news coming out of my hometown, praying for all affected by this horrific situation," Murray said. "My thoughts are with the victims and their families." US stock car auto racer Kyle Busch, second in the championship chase as the season winds down, was also struggling with the Vegas slayings. "Devastated to hear of the senseless tragedy in my hometown," he tweeted. "My thoughts and prayers are with all of you." The National Hockey League's first-year Vegas Golden Knights, the city's first major US sports league team set to open their inaugural season Friday, tweeted support for first responders and condolences to the victims. "We extend our thoughts, prayers and heartfelt condolences to the victims, their families and all those affected by the tragic events that took place on the Las Vegas Strip Sunday night," the team tweeted. "We are grateful for our city's brave first responders, law enforcement and medical personnel and the courage they demonstrated under unimaginable circumstances. We join in our city's mourning and offer our full support to the people of Las Vegas to help grieve, heal and persevere." The NFL's Oakland Raiders, set to move to Las Vegas for the 2020 season, sent out a statement about their future home, saying, "The Raiders family is shocked and saddened by the tragedy in Las Vegas and our thoughts and prayers are with the victims, families and first responders. The heart of the Raider Nation goes out to Las Vegas." NBA superstar LeBron James of the Cleveland Cavaliers expressed his shock as well, tweeting, "Pray for Vegas!! What the hell is going on people!?!? My prayers sent to the heavens above for all the families."University of Nevada Las Vegas ice hockey assistant coach Nick Robone was among those shot at the concert, according to the team's twitter page. He suffered a bruised lung and was in intensive care following surgery but is expected to make a full recovery after being hospitalized indefinitely. The reigning Super Bowl champion New England Patriots tweeted "our hearts are with everyone affected by last night's tragedy in Las Vegas" while the reigning World Series baseball champion Chicago Cubs tweeted, "We are deeply saddened by the tragic shooting in Las Vegas." 'Shocking in its cruelty'Russian President Vladimir Putin on Monday expressed his condolences in a message to US leader Donald Trump, saying a deadly mass shooting in Las Vegas was "shocking in its cruelty." "The crime that has taken the lives of tens of peaceful civilians is shocking in its cruelty," Putin said according to a statement from the Kremlin. It said the Russian president had expressed the words of support to the families of the victims.