A top American environmentalist group today slammed the over its ruling against India's solar localisation policies for US firms.

Alleging that almost half of US states have a programme like that of India, the top environmentalist group urged the US to drop its case against India.

Read more from our special coverage on "WTO" US lauds WTO ruling against Indias localisation rules

"The ruling is a step in the wrong direction, away from the climate progress that the global community committed to achieve in December's Paris climate agreement," Ilana Solomon, director of the Sierra Club's Responsible Trade Program, said after ruled against what it described as a common-sense solar energy initiative in India that is a core component of the country's contribution to the Paris agreement to tackle climate disruption.

By offering solar power companies government subsidies and long-term contracts, India's programme has already rapidly scaled up solar energy.

The programme aims to achieve 100,000 megawatts of solar power capacity by 2022 — more than the current solar capacity of the world's top five solar producers combined, it argued.

The WTO ruled against India's ambitious solar programme because its first phase requires power companies to use solar cells and modules made in India in order to benefit from the government-subsidised programme.

"Clean, renewable energy like solar is becoming cheaper in the US and abroad, creating new jobs, helping us move beyond coal and other dirty fuels and solve the climate crisis. We cannot afford to let decades-old, over-reaching trade rules trump policies that can create new green jobs and accelerate the transition to 100% clean energy," Solomon said.

"Almost half of US states have programmes that, like India's, offer incentives for renewable energy production that creates local, green jobs. The US should drop this case to avoid undermining climate protections abroad and at home," Solomon demanded.

"This decision is a warning against expansive trade deals like the Trans-Pacific Partnership that would replicate rules that undermine clean energy initiatives and constrain climate progress. Destructive trade deals like the Trans-Pacific Partnership go far beyond trade and interfere with commonsense policies needed to solve the climate crisis," the group said.

"Congress should view this ruling as another reason to stand up for green jobs and climate action by rejecting the Trans-Pacific Partnership," Solomon said.

The Sierra Club is America's largest and most influential grassroots environmental organisation, with more than 2.4 million members and supporters.