US Treasury Secretary Janet Yellen said Sunday that her talks with top Chinese officials have put ties on "surer footing", as she wrapped up a trip aimed at stabilising fraught relations between the world's two biggest economies. During her four-day trip -- which came on the heels of US Secretary of State Antony Blinken's visit -- Yellen stressed the need for greater exchanges and collaboration, even as deep divides persist between the countries. "We believe that the world is big enough for both of our countries to thrive," she told journalists at the US embassy in Beijing on Sunday. "Both...