The Federal judge overseeing negotiations toward a U.S. settlement of the Volkswagen diesel-emission cheating scandal said Tuesday that good progress was being made toward reaching a final resolution by June 21.

The Environmental Protection Agency and Volkswagen are on track to file a final agreement for public comment, said U.S. District Judge Charles Breyer.

But a number of issues remain to be worked out, including the amounts of fines to be paid by the automaker for willfully violating U.S. emission laws for eight years.

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The settlement will cover 482,000 Volkswagen and Audi TDI diesel cars fitted with 2.0-liter turbodiesel four-cylinder engines.

Cars and SUVs from VW, Audi, and Porsche that were fitted with a larger 3.0-liter V-6 turbodiesel are the subject of completely separate settlement negotiations.

In the case of the TDI four-cylinder diesels, the settlement will require VW to buy back the affected cars or modify them so they comply with U.S. emission laws.

Consumer Reports tests 2015 Volkswagen Jetta TDI diesel in 'cheat mode,' October 2015 [video frame]

Consumer Reports tests 2015 Volkswagen Jetta TDI diesel in 'cheat mode,' October 2015 [video frame]

VW will also have to pay "substantial" fines, and separately, fund additional measures to mitigate environmental damage by motor vehicles within the U.S.

Judge Breyer issued his interim report on Tuesday morning; it was covered that day by Reuters and many other news outlets.

In it, he praised the efforts of all the attorneys involved in working toward a settlement, as well as Special Master Robert Mueller.

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All parties have devoted "extensive daily efforts" to the negotiations, Breyer said.

Following the release of the judge's report, Volkswagen Group of America released the following statement:

Volkswagen is pleased that we continue to make progress in our discussions with U.S. government agencies, regulators and the Plaintiffs' Steering Committee, and is working to finalize the agreements in principle, as directed by the Court.

2012 Volkswagen Passat TDI Six-Month Road Test

2012 Volkswagen Passat TDI Six-Month Road Test

These agreements in principle are an important step on the road to making things right, as we work to earn back the trust of our customers, dealers, regulators and the American public.

We also continue to work expeditiously on an approved solution for 3.0L V-6 engine TDI vehicles.  Our customers in the United States do not need to take any action at this time, and we thank them for their continued patience.

Assuming the proposed settlement is released on schedule on June 21, owners, regulators, and other parties will have five weeks to comment on its details.

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Judge Breyer has set July 26 as the day for all parties to agree to a final settlement.

The Volkswagen diesel scandal has led to increased focus on both emissions and fuel-economy testing among automakers globally.

Several other manufacturers are now being investigated over allegations that their vehicles emit far more in real-world usage than is permitted under law, even though they may have successfully passed specific tests.

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