The letter from the labor federation’s president, Richard Trumka, was addressed to National Security Adviser Jake Sullivan. Trumka singled out products that 'contain polysilicon made with forced labor', reports Bloomberg.

“These products must have no place in our efforts to fight climate change,” Trumka was quoted as saying by Bloomberg.

China's government has often drawn flak over its treatment of the Uyghur Muslims of the Xinjiang region.

The region produces more than half the world’s supply of polysilicon, a metal that is a critical component in photovoltaic cells that turn the sun’s rays into electricity, reports Bloomberg.

“The region’s outsized role in the global solar energy product supply chain and convincing evidence of systematic forced labor in the Uyghurs region’s solar production demands immediate focused action,” Trumka said in the three-page letter.