The partial US government shutdown is not preventing the North American Aerospace Defense Command (NORAD) from tracking Santa Claus as he embarks on his global trek to deliver Christmas gifts to children across the world, the command said on Monday.A holiday tradition, which allows parents and children to track Santa Claus online on his globe-trotting journey, will continue on Christmas Eve even though NORAD receives funding from the Department of Defense.NORAD, a joint US and Canadian command responsible for aerospace and maritime control and warning missions, is “on duty 24/7, 365 days a year…committed to protect the citizens of both our countries," the agency said in a statement.Those duties include the decades-long Yuletide custom of shadowing Santa Claus on his reindeer-powered sleigh, it said.“Santa is under way and we are tracking him,” said US Army Lieutenant Colonel Mary Ricks, spokeswoman for NORAD, which is based in Colorado Springs, Colorado.NORAD's Santa-tracking website, www.noradsanta.org, provides real-time animated updates of the worldwide journey. The site attracts nearly 1 million unique visitors annually. Some 1,500 volunteers, both civilian and military, staff the computers and a Santa hotline.The tradition started in 1955 when a Sears Roebuck department store in Colorado Springs misprinted the phone number to the North Pole in a newspaper advertisement for kids to call in and speak to Santa.Instead, the number rang to what was then called the Continental Air Defense Command, according to NORAD's website. The commanding officer at the time, US Air Force Colonel Harry Shoup, fielded multiple calls from children eager to speak to Santa, who is also known as Kris Kringle, Father Christmas or St. Nicholas.Shoup assured the children that Santa had taken off from his home base at the North Pole and was delivering gifts to good girls and boys across the globe.Renamed NORAD three years later as a combined Canadian and US agency, the Santa-tracking tradition has continued. It now employs social media sites and smart phone apps to spread the word on Santa's whereabouts.Ricks said Santa is tracked by infrared signals emitted by the shiny red nose of Rudolph, Santa’s lead reindeer.Once Santa’s sleigh enters North American air space, a squadron of Canadian and US fighter jets are scrambled to escort Santa, who must slow down to greet the pilots as he travels at “the speed of starlight,” Ricks said.