The United States has hit the 19 million-mark for COVID-19 cases Sunday, adding one million in less than a week. 

According to data from Johns Hopkins University, the number of cumulative infections in the U.S. surpassed 19 million on Sunday, with the death toll exceeding 333-thousand. 

The U.S. topped 18 million cases on December 21 and added one million in six days.  

It took 98 days for the U.S. to hit its first one million cases from the outbreak on January 20, but the pace of increase has been growing steeply in recent months. 

Earlier this month, the U.S. added one million cases to reach 16 million in four days, the shortest period for one million cases. It also took just four days for the number to rise from 17 million to 18 million.