The US election was plunged into chaos early Wednesday as President Donald Trump prematurely declared victory and sought Supreme Court intervention to stop vote-counting -- even as his Democratic rival Joe Biden voiced confidence in his own chances. In a divisive election cast under the shadow of the coronavirus pandemic that has claimed more than 230,000 lives in the United States, Trump appeared to have avoided a Democratic wave predicted by some polls but he still needs key states to secure another four-year term.