WASHINGTON (REUTERS) - United States Treasury Secretary Janet Yellen on Wednesday (June 23) warned Congress that the US risks a debt default and a new financial crisis as soon as August if lawmakers fail to act quickly to suspend or raise the federal borrowing limit. In testimony to a Senate appropriations sub-committee, Dr Yellen said defaulting on US debt obligations would be "unthinkable" and "would have absolutely catastrophic economic consequences". Dr Yellen said that to avoid uncertainty for financial markets, Congress should pass new debt limit legislation - allowing the Treasury to continue borrowing - before the latest suspension expires on July 31. A first-ever default on US government debt obligations "would precipitate a financial crisis, it would threaten the jobs and savings of Americans at a time when we're still recovering from the Covid pandemic", Dr Yellen said. "I would plead with Congress to simply protect the full faith and credit of the United States by acting to raise or suspend the debt limit as soon as possible." The Treasury in the past has been able to stave off potential default for several months by employing extraordinary cash flow management measures...