U.S. President Barack Obama on Monday signed into law legislation that gives him "fast-track" power to push ahead on a Pacific Rim trade deal that has been the subject of intense debate in Congress and across the nation.

Flanked by some of the lawmakers who supported the bill through a six-week congressional battle, Obama acknowledged that his fight to secure the 12-nation Trans-Pacific Partnership was far from over.

"We still have some tough negotiations that are going to be taking place," Obama said at a signing ceremony. He noted that lawmakers and the public will be able to scrutinize the trade deal before it is finalized. "The debate will not end with this bill signing," he said.