Volkswagen's (VOWG_p.DE) top labor representative has dubbed the carmaker's U.S. operations a "disaster" and urged more models and swifter decisions to help revive the German group's declining fortunes in the world's second-largest auto market.

While VW has risen to become the biggest automaker in China and Europe, the group still hasn't fully understood how to succeed in the United States, Bernd Osterloh, VW's works council chief, told reporters in Wolfsburg on Wednesday.

"The U.S. are a case of disaster" for VW, said Osterloh who also sits on the carmaker's supervisory board.

The German multi-brand group last month ousted U.S. divisional chief Jonathan Browning who oversaw the much-lauded 2011 launch of the midsize Passat, sales of which declined 6.3 percent last year following a 2011-12 surge.

Osterloh echoed criticism from the company's new head of U.S. operations, Michael Horn, who earlier this month faulted VW headquarters for paying little heed to the dynamics of the U.S. market.

VW's situation in the United States, where the company has been grappling with losses for years, won't improve until 2016 and it needs more models there, including a pick-up truck, Osterloh said.

VW announced at the Detroit auto show plans to make a sport-utility vehicle (SUV) for North America as part of a $7 billion investment in the region.

Osterloh lamented that a year after the "CrossBlue" SUV was unveiled, it's still unclear where the model will be built.