President Obama today called on Congress to pass an immigration bill in the coming weeks, saying lawmakers need to "work up the political courage" to fix the nation's broken immigration system.

"I expect a bill to be put forward. I expect the debate to begin next month," the president said at a naturalization ceremony at the White House. "I want to sign that bill into law as soon as possible."

Welcoming new citizens to the United States, the president argued "immigration makes us stronger. It keeps us vibrant. It keep us hungry. It keeps up prosperous."

The president praised lawmakers for the bipartisan progress that has been made so far. "We've seen some real action in Congress," he said. "There are bipartisan groups in both the House and the Senate working to tackle this challenge, and I applaud them for that. We are making progress. But we've got to finish the job."

During the ceremony 28 people representing 26 countries, including 13 service members, took the oath of allegiance and became naturalized U.S. citizens.

"The promise we see in those who come from all over the world is one of our greatest strengths," Obama said. "It's helped to build the greatest economic engine that the world has ever known. And you think about the drive and the determination that it took for each of these 28 men and women to reach this moment. Imagine how far they'll go from here, the kind of difference that they'll be making on behalf of this country."