BEIJING (Reuters) - President Barack Obama gave his sternest warning yet about the need to contain rising U.S. deficits, saying on Wednesday that if government debt were to pile up too much, it could lead to a double-dip recession. With the U.S. unemployment rate at 10.2 percent, Obama told Fox News his administration faces a delicate balance of trying to boost the economy and spur job creation while putting the economy on a path toward long-term deficit reduction.