(Reuters) - Officials from the U.S. government asked UnitedHealth Group (NYSE:) to expedite payments to healthcare providers in an open letter on Sunday, after a hack of the insurer's Change Healthcare (NASDAQ:) 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."

While the letter specifically named UnitedHealth and addressed the recent hack, it also asked other companies in the industry to help.

"We call on UHG, other insurance companies, clearinghouses, and health care entities to take additional actions to mitigate the harms this attack places on patients and providers, particularly our safety net providers," the letter said.

UnitedHealth did not immediately respond to a request for comment.

The U.S. government said last Tuesday it would accelerate Medicare and Medicaid payments to some hospitals hurt by the cyber attack on Change Healthcare late last month.

The cyberattack on Change, disclosed on Feb.21, was perpetrated by hackers who identified themselves as the "Blackcat" ransomware group and has had a knock-on effect on players across the U.S. healthcare system.

Disruptions triggered by the attack have impacted electronic pharmacy refills and insurance transactions.

UnitedHealth has said it expects to restore disrupted services for medical claims and payments platforms by mid-March.