BERLIN — Italy has come under pressure over how it regulates Fiat Chrysler, which Germany and the U.S. accuse of using software that can allow some diesel engines to emit more pollution than legally permitted.

The European Union’s executive branch said Friday it is following up on German complaints against Italy.

German Transport Ministry spokeswoman Svenja Friedrich noted that Fiat Chrysler had refused to meet German authorities over the issue, and Italy had canceled a “mediation” meeting with the European Commission scheduled for the end of the month.

“We urge the EU Commission to insist on a new appointment in the near future,” Friedrich said. The Commission said Friday that it has repeatedly asked the Italian authorities to come up with convincing explanations on the emissions of the model and is continuing its efforts.

The Commission has a limited role in emissions regulation and is seeking to act as a go-between for Germany.

In the EU, each nation’s regulators have the responsibility of enforcing the rules on companies, but they may be more or less stringent.

Carmakers can choose the EU country where they want their cars tested for emissions controls. Because the emissions criteria are set for the bloc as a whole, approval in one country means that type of vehicle can be registered in any of the other 27 member states as well.

The comments come a day after the U.S. government accused Fiat Chrysler of failing to disclose software in some 104,000 vehicles of its pickups and SUVs with diesel engines that allows them to emit more pollution than allowed under the Clean Air Act.

The use of such software has come under extra scrutiny since German automaker Volkswagen admitted to using them to cheat on diesel emissions tests in the U.S.

Fiat Chrysler CEO Sergio Marchionne has denied wrongdoing in response to the U.S. probe.

Italian consumer group Altroconsumo called on Italy’s Transport Ministry to distribute data on diesel emissions in Italy, saying it had pledged to do so in September 2015 but had not yet followed through. Altroconsumo is heading up a class-action suit against Volkswagen in Italy, with more than 23,000 VW buyers joining the case so far.

Another consumer group, Codacons, said Friday it was making a formal request to prosecutors to investigate whether any of the engines being investigated in the U.S. are sold in Italy.