By Deborah Charles

CHICAGO, Jan 3 (Reuters) - President-elect Barack Obama on Saturday said the struggling U.S. economy could face more challenges and urged lawmakers to act quickly on recovery proposals even as some Republicans expressed concerns about plans for a huge stimulus package.

"As we mark the beginning of a new year, we also know that America faces great and growing challenges -- challenges that threaten our nation's economy and our dreams for the future," Obama said in his weekly radio and Internet address.

"For too many families, this new year brings new unease and uncertainty as bills pile up, debts continue to mount and parents worry that their children won't have the same opportunities they had,"

Obama, who takes office on Jan. 20, said he would meet next week in Washington with Democratic and Republican leaders to discuss his plan aimed at bolstering the U.S. economy and creating 3 million jobs.

"However we got here, the problems we face today are not Democratic problems or Republican problems," he said. "These are America's problems and we must come together as Americans to meet them with the urgency this moment demands."

Obama said economists agreed that if the United States does not act "swiftly and boldly, we could see a much deeper economic downturn that could lead to double-digit unemployment and the American dream slipping further and further out of reach."

GOAL OF 3 MILLION JOBS

He said the country needed an economic recovery and reinvestment plan to create jobs in the short-term and spur economic growth and competitiveness in the long term.