(Reuters) - Officials from the U.S. government asked UnitedHealth Group to expedite payments to healthcare providers in an open letter on Sunday, after a hack of the insurer's Change Healthcare tech unit crippled medical claims and payments.

Officials from the U.S. Department of Labor and the U.S. Department of Health and Human Services urged UnitedHealth (UHG)to take "responsibility to ensure no provider is compromised by their cash flow challenges stemming from this cyberattack on Change Healthcare."