China's Commerce Ministry said today it's "greatly concerned" about the United States' investigation into Chinese solar panel companies operating there. China warned the probe could jeopardize bilateral cooperation on energy issues.

The U.S. Commerce Department said yesterday, it would investigate whether these companies were selling solar panels at unfair discounts and/or receiving illegal government subsidies back home.

Analysts say the trade dispute between the two countries could lead to steep duties on imports of Chinese panels and help struggling domestic manufacturers in the U.S.