US Treasury Secretary Janet Yellen has warned companies in China against exporting products to Russia that could be used for Moscow’s war against Ukraine. “I stressed that companies, including those in [China], must not provide material support for Russia’s war and that they will face significant consequences if they do,” she said on Monday in Beijing at the end of her trip to China. Yellen said all banks that transfer money to Russia in order to supply the Russian defence industry with military or other goods are at risk of US sanctions, too. The US has already rolled out a raft of sanctions …