WASHINGTON, Dec 1 (Reuters) - U.S. President-elect Joe Biden’s treasury secretary nominee Janet Yellen said on Tuesday the country is facing a historic crisis from the pandemic and the subsequent economic fallout. “It’s an American tragedy and it’s essential that we move with urgency. Inaction will produce a self-reinforcing downturn, causing yet more devastation,” Yellen said. Reporting by Tim Ahmann and Nandita Bose in Washington; Editing by Chris Reese