"I have become more and more concerned by this sorry state of affairs," wrote White House Drug Control Director Rahul Gupta.
New emails suggest doping was not limited to Olympic sports.
A report found up to half of anti-doping tests could not be completed.
Steven Colvert tested positive for blood-booster EPO in 2014.
'Fancy Bear' has been releasing details of athletes' Therapeutic Use Exemptions.
A Moscow lab protected athletes and the Russian ministry of sport oversaw manipulation of samples, according to WADA.
The tennis world No. 6 faces a provisional suspension on March 12.
The country has failed to satisfy the World Anti-Doping Agency's demands.
Sir Craig Reedie speaks to Newsweek in the second part of an exclusive interview.
Sir Craig Reedie speaks to Newsweek on the difficulties of restoring faith in sport.