Volkswagen's plan to fix the cars affected by its emissions scandal in the US have been rejected by government officials.
In a statement, California's Air Resources Board (CARB) said it has rejected proposals put forward by VW to rectify cars with its 2.0-litre diesel engine, saying the proposals lack detail and contain gaps in information.
The CARB also says that VW's documentation lacks enough information for a "technical evaluation", as well as not addressing "overall impacts on vehicle performance, emissions and safety."
CARB chair Mary D Nichols said: "They continued and compounded the lie, and when they were caught they tried to deny it. The result is thousands of tons of nitrogen oxide that have harmed the health of Californians. They need to make it right."
Volkswagen boss Matthias Müller is due to meet with Gina McCarthy, the head of the United States Environmental Protection Agency (EPA), later today.
A response from Volkswagen stated: "Today's announcement addresses the initial recall plans Volkswagen submitted to CARB in December. We are committed to working co-operatively with CARB and other regulators, and we plan to continue our discussions when we meet with the EPA."
Although the CARB's statement does not openly discuss more financial compensation for US owners, the group says it will "continue its investigation and technical evaluations with the EPA to return the vehicles to legally required emission levels, determine mitigation for past and future environmental harm, and assess penalties."
Although this rejection only applies to VW's fix for 2.0-litre engines, a fix for the firm's 3.0-litre engines is due to be submitted to CARB next month.