Iran, China, and Russia fired a diplomatic salvo Friday, jointly denouncing the U.S. “maximum pressure” campaign against Tehran in a statement released after a Beijing powwow of their deputy foreign ministers.

China is hosting diplomats from Iran and Russia for talks on Iran’s nuclear program Friday as Beijing aims to position itself as a power broker on an issue seen internationally as a pressing security concern.

China, Russia, and Iran held talks in Beijing demanding an end to US sanctions on Tehran, while a sanctions expert expressed skepticism about lifting sanctions as a precondition for negotiations.