Volkswagen said Tuesday that it is in "advanced talks" with United States authorities over a proposed settlement in its diesel emissions scandal under which the company would pay $4.3 billion in criminal and civil fines.

The draft settlement would include the appointment of an independent monitor for three years.

A company statement issued Tuesday said that under the proposal Volkswagen would agree to "a guilty plea" to criminal law provisions.

The draft needs to be approved by Volkswagen's boards and U.S. courts. Volkswagen said its management board of top executives, which includes CEO Matthias Mueller, and its board of directors would deal with the issue "in the very short term," as soon as Tuesday or Wednesday.

"A final conclusion of the settlement agreement is further subject to the execution by the competent U.S. authorities and to the approval of the competent U.S. courts," the company said.

The penalties would exceed what the company has set aside to cover costs from the scandal but the specific impact on 2016 earnings "cannot be defined at present."

Volkswagen has admitted equipping diesel cars with software that turned up emissions controls when the car was being tested, and turned them down during normal driving, improving engine performance but exceeding emission limits.

The company has agreed to a $15 billion civil settlement with environmental authorities and car owners in the U.S.