Washington says the duties caused a USD 250 million annual drop in exports.
The ruling concerns grain oriented flat-rolled electrical steel that is used primarily by the power generating industry. The WTO ruled in November 2012 that China had unfairly imposed antidumping and countervailing duties.
China has reduced its countervailing duties, but the US contends that step was insufficient.
The US says it's the first time it is challenging Beijing's compliance with a WTO ruling.
The US today sought consultations with China within 15 days. If it is not satisfied by China's response, it can refer the case back to the WTO and potentially seek redress.