Janet Yellen has vowed to “keep at it” and carry on building closer ties between the world’s two economic superpowers, despite the US Treasury secretary’s nearly week-long trip to China yielding little progress on disagreements over how Beijing should counter its slowdown.Yellen flew back to the US on Tuesday after visiting the southern manufacturing and export hub of Guangzhou and then Beijing. China rolled out the red carpet — including a private visit to the Forbidden City — for Yellen, who said the bond between the world’s two largest economies had strengthened since her shorter visit in July.

Yet Chinese officials later pushed back at many of Yellen’s main talking points, especially US complaints of Chinese excess capacity and dumping. There were few signs of progress on the sticking point of China’s subsidies for its green-tech industry, which Treasury officials said risked flooding global markets with cheap goods.

Yellen refused to be drawn on how the US could retaliate but said the Biden administration would move to stop any repeat of 10 years ago, when China dumped cheap steel on to global markets, hurting foreign competitors and costing its trading partners jobs.