US President Barack Obama urged lawmakers from both parties Friday to back his economic stimulus package, saying the US economy's dire problems require congressional action even if some members object to portions of the plan. "I know that it is a heavy lift to do something as substantial as we're doing right now," Obama said as he sat down with House and Senate leaders from both parties at the White House. Republican members, especially, have objected to some of the $825 billion plan. "I recognize that there are still some differences around the table and between the administration and members of Congress about particular details on the plan," he said. "But I think what unifies this group is a recognition that we are experiencing an unprecedented, perhaps, economic crisis that has to be dealt with, and dealt with rapidly." He thanked congressional leaders for working quickly, even through some holiday periods, to move the rescue package he says will create 3 million to 4 million new jobs.