WASHINGTON, Jan 19 (Reuters) - Janet Yellen, U.S. President-elect Joe Biden’s nominee for Treasury Secretary, will urge lawmakers on Tuesday to “act big” on the next coronavirus relief package, adding that the benefits outweigh the costs of a higher debt burden. In prepared testimony at her confirmation hearing, Yellen said her task as Treasury chief will be to help Americans endure the final months of the coronavirus pandemic, and rebuilding the U.S. economy “so that it creates more prosperity for more people and ensures that American workers can compete in an increasingly competitive global economy.” Biden, who will be sworn into office on Wednesday, outlined a $1.9 trillion stimulus package proposal last week, saying bold investment was needed to jump-start the economy and accelerate the distribution of vaccines to bring the virus under control. “Neither the president-elect, nor I, propose this relief package without an appreciation for the country’s debt burden. But right now, with interest rates at historic lows, the smartest thing we can do is act big,” Yellen, a former Federal Reserve chair, said in prepared remarks to the Senate Finance Committee. “I believe the benefits will far outweigh the costs, especially if we care about helping people who have been struggling for a very long time,” she said in the statement, which was obtained by Reuters. The proposed aid package includes $415 billion to bolster the U.S. response to the virus and the rollout of COVID-19 vaccines, some $1 trillion in direct relief to households, and roughly $440 billion for small businesses and communities particularly hard hit by the pandemic. Many Americans would receive stimulus payments of $1,400, which would be on top of the $600 checks approved in a pandemic relief bill passed by Congress last month. Supplemental unemployment insurance would also increase to $400 a week from the current $300 a week, and it would be extended to September. Yellen received an endorsement from all former Treasury secretaries, from George Schultz to Jack Lew, who urged senators in a letter to swiftly confirm Yellen’s nomination so she can quickly tackle “daunting challenges” in the economy. “Addressing these pressing issues will require thoughtful engagement by the Department of the Treasury. Any gap in its leadership would risk setting back recovery efforts,” the former secretaries wrote. A spokeswoman for departing Treasury Secretary Steven Mnuchin, who steps down on Wednesday, could not immediately be reached for comment. Analysts also expect Yellen to address the Treasury’s stance on the dollar, after President Donald Trump frequently called for a weaker dollar to boost U.S. exports. Treasury Secretaries have previously affirmed their commitment to a market-determined exchange rate and some in recent years have said that a strong dollar is in U.S. interests. (Reporting by David Lawder, Andrea Shalal and David Shepardson; Additional reporting by Trevor Hunnicutt; Editing by Andrea Ricci)