Washington, June 30 : Deborah Birx, head of the White House Coronavirus Taskforce, has called on local authorities to expand testing as the us continues to grapple with the largest outbreak in the world. In a call with the country's governors on Monday, Birx identified the states of Texas and Arizona as "signficant hotspots", and said the task force wanted to help "deploy some new testing techniques to really test large populations at the community level", the BBC reported citing CBS News. "Although our mortality continues to decline week over week, we believe this week it will stabilize, with the potential of going back up if we don't intervene comprehensively now," she added. As of Tuesday morning, the US accounted for 2,588,582 COVID-19 cases, with 126,133 deaths, according to the Johns Hopkins University. Both tallies are currently the highest in the world. On June 26, the US reported the highest number of new cases in a single day, with at least 40,173 new infections. Thirty-six states were reporting a rise in COVID-19 cases. During Monday's call Anthony Fauci, America's top infectious disease expert, said young people needed to understand they had a role to play in helping to contain the spread. "We don't want to go back to shutdown," he added. "We want to let the public health process be the vehicle to opening up, not the obstacle to opening up." The call came a day after US Secretary of Health and Human Services Alex Azar said the "window is closing" for the country to curb the surge of coronavirus cases. "Things are very different from two months ago... So it is a very different situation, but this is a very, very serious situation and the window is closing for us to take action and get this under control," Xinhua news agency quoted Azar as saying in a CNN interview on Sunday. Azar said that in many southern states where the virus is spiking, including Florida and Texas, the majority of the cases were people under 35, and a large number of those will be asymptomatic. Azar said the administration is working with local authorities and states to understand why the virus is surging in certain areas. He noted that treatments like steroids and remdesivir were now available for COVID-19, and encouraged people who have had the virus to donate plasma to increase the supply. /IANS