The U.S. does "not have high confidence in the information coming out of China" regarding the count of coronavirus cases, a senior administration official told CNBC.
The official also noted that China "continues to rebuff American offers of assistance."
There are more than 60,000 confirmed cases of virus, with the vast majority occurring in China, and over 1,300 people have died. After several days of reporting a slowing number of new cases, Chinese officials said on Thursday there was more than 15,000 additional cases. The majority of those came from a change in how the numbers were reported, with the "clinically diagnosed" cases now counting as "confirmed."
There has been skepticism among researchers that the official numbers reflect how contagious the virus truly is. An article published last month in the medical journal Lancet estimated that there were already more than 75,000 cases in China as of Jan. 25.
Reuters reported that National Economic Council Director Larry Kudlow also said on Thursday that there does not appear to be good transparency by China regarding the outbreak.
The World Health Organization sent an advance team to the country on Sunday.
The outbreak has caused turmoil in markets around the world, especially in the stocks of companies with high exposure to China through their supply chains or key sources of revenue.There have been travel restrictions and factory closures in China during the outbreak, leading market strategists to slash their projections for the country's first quarter GDP.