Washington, Dec 3 : US President-elect Joe Biden has urged all Americans not to travel during the upcoming holiday season due to the unabated coronavirus resurgence in the country, which is currently the worst-hit in the world. "You cannot be traveling during these holidays, as much as you want to," Biden said from Wilmington, Delaware, on Wednesday during a virtual roundtable with a group of workers and small-business owners impacted by the pandemic. The remarks were made several days after Thanksgiving, during which millions of Americans travelled, and some three weeks before Christmas, reports Xinhua news agency. "Christmas is going to be a lot harder," said Biden, adding that the country is "likely to lose another 250,000 people" in coming months "because people aren't paying attention". Biden highlighted his own small gathering during Thanksgiving, which broke a decades-old tradition of large family gatherings and asked Americans to heed the advice of public health experts and pass on large get-togethers later this month. "Christmas is going to be a lot harder," the former Vice President added. Robert Redfield, director of the US Centers for Disease Control and Prevention, also issued a stark warning on Wednesday. "The reality is December and January and February are going to be rough times. I actually believe they're going to be the most difficult time in the public health history of this nation," Redfield told an event hosted by the US Chamber of Commerce. Biden and Redfield's warnings come as the US is currently the worst-hit country by the coronavirus pandemic with the highest number of cases and fatalities, according to Johns Hopkins University. In its latest update on Thursday, the University's Center for Systems Science and Engineering (CSSE) revealed that the country's overall caseload and death toll stood at 13,916,543 and 273,316, respectively. /IANS