US Treasury Secretary Janet Yellen called on Pacific Rim finance ministers to boost the productive capacity of their economies while working to finance the transition to low-carbon energy and provide more opportunities for the poor. <br />''<br />''Opening a meeting of finance ministers of the Asia Pacific Economic Cooperation countries in San Francisco in US yesterday, she said the group's economic dynamism meant the actions they take matter for addressing global challenges. Finance chiefs from 21 Pacific Rim economies, including the United States, Japan and China, began their meeting in San Francisco on Sunday. <br />''<br />''The ministers exchanged views on how to implement fiscal reforms, taking into consideration the economic situation of each nation. The ministers are expected to discuss how to push the rollout of renewable energy financially with the aim of tackling climate change.<br />''The APEC summit is scheduled to open tomorrow as part of a series of APEC meetings that continue until Friday.<br />