CHICAGO/DETROIT, Oct. 14 (Yonhap) -- South Korean President Lee Myung-bak visited an auto plant in Detroit, along with U.S.

President Barack Obama on Friday, promising American auto workers that a free trade agreement between the two countries will help protect their jobs and create more work for Americans.

"Some of you may think that the FTA will cost you your jobs.

But that is not the case," Lee, wearing a Detroit Tigers cap, told hundreds of workers at the plant. "President Obama and I can promise you here that the FTA will protect your jobs and create even more work for others," he said, prompting a standing ovation.

"I expect that Detroit will become a more lively city."

The rare visit, which came after Congress approved the long-pending trade pact on Wednesday, is seen as a symbolic gesture aimed at underscoring the two leaders' commitment to the deal and dispelling concern among some American auto workers that it could hurt their employment.

"One thing is on the minds of both myself and President Obama.

That is how to create jobs and protect them. This is the same concern and task that I share with President Obama," Lee said, reassuring the auto workers. 

The two leaders flew from Detroit to General Motors Co.'s Orion assembly plant aboard Obama's Marine One helicopter.

Obama called the deal "a win-win for both of our countries."

"Here in the United States, this trade agreement will support at least 70,000 American jobs. It will increase exports. It will boost our economy by more than our last nine trade agreements combined," he said.

"And as I said, the good thing is we've got a balanced situation. It's not just a matter of folks sending a bunch of stuff here. Koreans are also buying American products. That's what makes it a win-win."

Obama called South Korea a "critically important" country," "one of the fastest-growing countries," and "one of our closest allies and our closest friends."

"And President Lee and I talked about this when we had dinner the other night. Our trade is basically balanced between the United States and Korea. They buy as much stuff from us as they sell to us and that's how fair and free trade is supposed to be. It's not a one-sided proposition. That's how trade is supposed to be," he said.

Obama went on to say: "If Americans can buy Kias and Hyundais from Korea, then I know Koreans should be able to buy some Fords and Chryslers and Chevys that are made right here in the United States of America."

The accord was first signed in 2007, but was modified last year to address U.S. concerns about the deal's possible impact on the struggling American auto industry. It calls for tearing down or reducing tariffs and other barriers to trade between the two countries.

Lee later visited South Korea's Hyundai Mobis-run auto parts plant in Detroit to promote the deal's benefits.

Later Friday, Lee flew to Chicago, Obama's political hometown, for a dinner meeting with business leaders of the two countries hosted by Chicago Mayor Rahm Emanuel, who served as Obama's chief of staff. The trade accord is expected to be a key topic there also.

Emanuel offered congratulations to Lee on the Congressional ratification of the pact, saying that it is a win-win deal beneficial to both nations. The agreement will further strengthen the solid friendship between the two nations, the mayor said.

Lee praised Emanuel for contributing to the deal when he was at the White House, and said he hopes Chicago will also benefit from the agreement. Lee also said that the pact will deepen the alliance between the two countries that he said was forged in blood during the 1950-53 Korean War.

Chicago is the last stop on Lee's five-day state visit to the U.S.

Lee plans to head home on Saturday after meeting with South Korean residents of Chicago.