(Reuters) - A lawyer for Volkswagen AG VOWG_p.DE told a federal judge on Thursday the German automaker is making progress in senior level settlement talks with the U.S. Justice Department, Environmental Protection Agency and California to reach a resolution over excess emissions in nearly 600,000 diesel vehicles.

Volkswagen's logo is seen at its dealer shop in Beijing, China, October 1, 2015. REUTERS/Kim Kyung-Hoon

Lawyer Robert Giuffra told U.S. District Judge Charles Breyer at a court hearing in San Francisco the automaker is making progress in trying to reach a settlement after it admitted to using software to emit up to 40 times legally allowable emissions in vehicles sold since 2009.

“The discussions are progressing,” Giuffra said.

The Justice Department last month sued VW for up to $46 billion for violating U.S. environmental laws.

Breyer said he wants a definite answer by March 24 from VW and the EPA on whether the sides have found an acceptable fix for the vehicles, noting that VW admitted the excess emissions nearly six months ago.

“This is an ongoing problem,” Breyer said, adding that he has a “sense of urgency” about seeing a resolution. VW said it wants to move soon.

“We are committed to resolving these matters as quickly as possible,” Giuffra said, noting that the issue impacts up to 11 million vehicles in 100 countries.

Giuffra told the court VW may have something more definitive to say in about a month or so, but declined to offer specifics of the talks, or of any proposals on the table. He said the Justice Department has asked VW not to discuss any aspect of the negotiations.

Giuffra said the talks have also included separate working groups on various topics including the remedy for vehicles owners, the approach for addressing the environmental harms caused by the vehicles and other issues like onboard diagnostic systems. He said VW has given written presentations to the Justice Department and environmental agencies.

Breyer previously named former FBI director Robert Mueller as a settlement adviser. Mueller has been holding talks and met with VW officials, including the senior engineer responsible for the fix. But Breyer wants VW’s senior management to meet with Mueller.

Breyer said VW compensation adviser, Ken Feinberg, cannot move forward on a framework for addressing owner claims until VW and EPA reach some agreement.