WASHINGTON—U.S. President Barack Obama on Saturday praised a newly sealed trade deal with South Korea as a landmark agreement that promises to boost the domestic auto industry and support tens of thousands of American jobs.

"This agreement shows the U.S. is willing to lead and compete in the global economy," the president told reporters at the White House, according to the Associated Press, calling it a triumph for American workers in fields from farming to aerospace.

The pact, which requires congressional approval, would be the largest since the North American Free Trade Agreement with Canada and Mexico in 1994. President Obama said the South Korean deal would support at least 70,000 American jobs—welcome news with the latest U.S. unemployment figures showing nearly stagnant job growth. The president said that jobs report showed more needed to be done.

"Essential to that is opening new markets around the world to products that are made in America," the president said. "Because we don't simply want to be an economy that consumes other countries' goods."

Negotiators for the U.S. and South Korea—the world's No. 1 and No. 15 economies, respectively—broke a three-year impasse over the bilateral agreement early Friday by reaching accord on a deal to gradually lower U.S. tariffs on Korean automobiles.