Gov. Phil Murphy and the state's health commissioner spoke during their daily briefing Friday about the low response rate to contact tracers is affecting the state's ability to stop the spread of the coronavirus.

Health Commissioner Judith Persichilli is urging people to answer calls from contact tracers who are trying to track down people exposed to COVID-19. She says too few people are taking those calls.

"The greatest impediment to contact tracing has been from people not answering that important phone call or worse yet, refusing to assist our contact tracers," says Gov. Murphy.

The health commissioner says 45% of the cases are not providing details on their close contacts. That means people don't know they were exposed.

MORE: Protect yourself: Preventing a contact tracer scam

"If you are concerned it is a scam, hang up and call your local health department and verify they are trying to reach you," says Persichilli.

Persichilli says contact tracers will never ask for your social security number, financial information or immigration status.

The Health Department unveiled a new online tool to track the progress of contact tracing. Currently just over 1,300 contact tracers are working statewide.

Sixty percent of cases referred to contact tracers have been followed up successfully. The health commissioner says that number should be 100% within 24 hours.