Virginia on Wednesday launched the first contact tracing app for the novel coronavirus in the United States that uses new technology from Apple Inc. and Alphabet Inc.'s Google.

The state is betting that the app, COVIDWISE, can help it catch new cases faster, though long delays in getting test results must be overcome in order for it to be effective.

Phones with the app exchange Bluetooth signals to keep an anonymous list of close encounters. The app then allows people who catch the virus to notify those contacts without anyone revealing their identity.

"This is a way we can all work together to contain this virus," Democratic Governor Ralph Northam said in a televised briefing. "No one is tracking you. None of your personal information is saved."

At least three more states are nearing the launch of similar apps, aiming to ease the burden on underfunded manual contact tracing teams.

But the United States remains far behind Europe, where millions of people across 11 territories over the last two months have downloaded smartphone tracker apps using the specialized Apple-Google Bluetooth technology.

A couple of U.S. states previously released contact tracing apps that experts have described as more privacy-invasive because they rely on tracking users' locations, as opposed to Bluetooth transmissions.