U.S. Vice President Mike Pence's chief of staff, Marc Short, has been diagnosed with COVID, making him the closest aide to the vice president and the latest senior official of the White House to be infected with the disease, Pence's spokesperson disclosed in a statement Saturday night following reports that another senior aide had also been infected.

"Today, Marc Short, Chief of Staff to the Vice President, tested positive for COVID-19, began isolating and assisting in the contact tracing process," Devin O'Malley, Pence's press secretary, said in a statement, adding that Pence and his wife both tested negative for the virus today, and "remain in good health," CNN quoted O'Malley as saying.

The confirmation comes as Pence embarks on a hectic election campaign for rallies in swing states in the run-up to the November U.S. presidential election as he and President Donald Trump fight to win another term. Based on reports, at least one more White House staffer in Pence's office has tested positive for COVID in the last few days.

As Trump returned to the White House from campaign rallies in Ohio, he said he was informed about Short's diagnosis, adding Short will be fine and that he is quarantining. A source with knowledge of the situation said that Marty Obst, a senior aide to the vice president, tested positive for COVID earlier this week.

Trump, who was diagnosed with the virus and was hospitalized on Oct. 2, has insisted that the U.S. has rounded the corner on the pandemic. Asked about the increase in coronavirus infections in Wisconsin, he said most individuals who contract get the disease recover.

Based on the guidelines of the Centers for Disease Control and Prevention (CDC), frontline personnel who have been exposed to the virus should have their temperature checked before work, wear a face covering at all times and observe physical distancing. Pence, who is chief of the White House Coronavirus Task Force, is set to spearhead a rally in Kinston, North Carolina, Sunday evening.

Short has been a key adviser involved with the country's pandemic response. He has been reported to have pushed for an economy-first approach to the ongoing global health crisis. Despite Pence having close contact with his chief of staff as recently as Friday, he plans to continue campaigning.

At least 34 people at the White House have been diagnosed with COVID earlier this month, including Trump's press secretary Kayleigh McEnany, senior adviser for policy Stephen Miller, campaign manager Bill Stepien, and external aides Chris Christie and Kellyanne Conway.