President Obama acknowledged Wednesday that some sectors of the U.S. economy will be harmed by a sweeping Pacific Rim free trade deal his administration is seeking, but he vowed that the benefits of the pact would far outweigh the costs.

"I've said there are losers. ... The question is, are there a lot more winners than losers? And the answer in this case is yes," Obama said during an interview with Kai Ryssdal, host of "Marketplace," the public radio show on business and the economy.

Obama emphasized that the United States would be foolish not to pursue more liberalized trade relations in Asia and elsewhere at a time when the global economy is becoming ever more intertwined.

"One of the basic premises for me in pursuing this  is that we can't just draw a moat and pull up the drawbridge around our economy," the president said. "We are completely woven into the global economy."

The interview was one of several Obama granted Wednesday as he ramped up his push on trade with just over week remaining before the House of Representatives is expected to vote on a fast-track trade promotion authority bill approved by the Senate last month. The legislation would help the administration finalize the 12-nation Trans-Pacific Partnership (TPP) and allow Obama to submit that accord to Congress for a vote on a specified timeline and without the possibility of lawmakers making amendments.

The president's trade initiative has faced fierce opposition from labor unions, environmental groups and Capitol Hill progressives, who fear that the TPP would lead to job losses and harm the economy. Anti-trade activists delivered a petition to lawmakers Wednesday with what they said were 2 million signatures on petitions opposing the deal.

"If there were ever a time a time in American history that we have got to stand up for the American worker and not for corporate greed, today is that day, and the TPP is that issue," Sen. Bernie Sanders (I-Vt.), a candidate for the Democratic nomination for the White House in 2016, said during a news conference outside the Capitol with other progressive opponents of the trade deal. "The facts are very clear. The TPP follows in the footsteps of other disastrous trade agreements."

In the "Marketplace" interview, Obama did not specify which industries would be harmed by the trade deal. The benefits of the pact, he said, "doesn't mean that there is not going to be some impact on some sectors of the economy, by definition. ... It may be that as a consequence of the trade deal, there are particular markets, there are particular niche parts of the economy, where we've got to provide help to transition [workers] and to retool and adapt."

The president said he empathized with the concerns of those Democrats who are opposing his push, but he said that the answer to economic concerns is "not to shut off trade."

Rather, he said, "we've got to continually adapt; we've got to be nimble" in a fast-changing world that continues to be disrupted by new technologies.

"We are completely woven into the global economy," Obama said. "We are the hub to many, to a large extent, of the global economy. So, the question is, how do we construct a set of rules, but then, also, how do we make sure that we're adapting and using the incredible advantages we have to the best of our ability."