European Union Competition Commissioner Neelie Kroes has slammed comments from the U.S. Department of Justice about Monday's European court ruling on an antitrust judgment against Microsoft.

[ Video: Commissioner talks Microsoft antitrust appeal | Plus: EC wins appeal, but MS dominates market | Ruling renews hope for developers | With MS ruling, a precedent for IT in Europe ]

Kroes described the criticism of the ruling as "totally unacceptable" during a news conference in Brussels on Wednesday.

The DOJ's Assistant Attorney General for Antitrust, Thomas Barnett, criticized the ruling sharply on Monday, warning that it could "have the unfortunate consequence of harming consumers by chilling innovation and discouraging competition."

Kroes fired back: "I think it's totally unacceptable [that a representative of the U.S. government] should criticize an independent court's decision. The Commission doesn't pass judgement on rulings in U.S. courts. We expect the same respect," she said.

On Monday, the Court of First Instance, Europe's second-highest court, dismissed an appeal by Microsoft against the Commission's 2004 antitrust ruling against the company.

The DOJ statement added: "In the United States, anti-trust laws are enforced to protect consumers by protecting competition, not competitors." Barring "demonstrable consumer harm, all companies, including dominant firms, are encouraged to compete vigorously."

Kroes, who plans to visit Washington, D.C., in the coming weeks, said that if Microsoft is unhappy with the court ruling it should appeal it to Europe's top court, the Court of Justice.