Treasury Secretary Janet Yellen appealed to China’s No. 2 leader not to let frustration over US curbs on access to processor chips and other technology disrupt economic cooperation during a visit Friday aimed at improving strained relations.

Meeting with Premier Li Qiang, Yellen said Washington and Beijing have a duty to cooperate on issues that affect the world. She appealed for “regular channels of communication” at a time when relations are at their lowest in decades due to disputes over technology, security and other irritants.