Yellen warns Beijing: Chinese firms aiding Russia face 'significant consequences'. U.S. Treasury Secretary Janet Yellen has expressed concerns about Chinese firms potentially aiding Russia's military efforts against Ukraine. During meetings with Chinese Vice Premier He Lifeng, Yellen emphasized the importance of not supporting Russia's defense sector and warned of significant consequences, including sanctions, for any companies involved. The US has already sanctioned several private firms and financial institutions, some in China, for aiding Russia. Yellen urged China to enforce crackdowns on such activities.