HONG KONG  Banks in China and Hong Kong began wiring Chinese renminbi directly to one another on Monday to settle payments for imports and exports, as China took another step toward establishing the renminbi as a global currency  and, eventually, an international alternative to the dollar.

China has tempered its recent calls for a global reserve currency other than the dollar going into a meeting of the world’s major industrialized countries and biggest emerging economies in Italy on Thursday. He Yafei, China’s vice foreign minister, said on Sunday that the dollar would remain the world’s dominant currency for “many years to come.”

But the Chinese government is accelerating the process of making its own currency, the renminbi, more readily convertible into other currencies, which gives it the potential over the long term to be used widely for trade and as a reserve currency.

The day that the renminbi is fully convertible  more than a few years away, but perhaps less than a few decades  will most likely signal a huge shift in global economic power, and a day of reckoning of sorts not just for China but also for the United States, which will no longer be able to run up huge debt without economic consequences.