South Korea's government says presidents Lee Myung-bak and Barack Obama have promised to resolve differences on a trade pact before Seoul hosts the Group of 20 leaders' summit next week.
The office of the South Korean president says Mr. Lee Tuesday morning telephoned Mr. Obama.
Presidential spokesman Cho Hyujin says the two leaders agreed to jointly complete work on the landmark free-trade agreement between the two countries.
The spokesman says the two presidents pledged to finalize the agreement before the G20 leaders' meeting, to promote free trade in the world and to upgrade the South Korean-U.S. alliance to a higher level.
The two presidents will meet next week in Seoul just before the leaders of the Group of 20 economic powers meet.
The U.S.-South Korea trade agreement was signed three years ago but the U.S. Congress has not ratified it.
Proponents of the agreement, such as the president of the American Chamber of Commerce in South Korea, Amy Jackson, call Tuesday's telephone pledge significant.
"That it was discussed by the leaders today, I think, is a very good sign that there's strong intention on both sides to get this done," said Jackson.
Some economic analysts predict the agreement could boost trade between the two countries by 25 percent. Last year, the United States' trade deficit with South Korea exceeded $10 billion.
U.S. proponents of the pact point out it would ultimately lift all tariffs between the two countries, increasing U.S. exports to South Korea by $10 billion annually and create thousands of new American jobs.
But U.S. critics, especially in the automotive and beef industries, say it does not give them enough access to the South Korean market.
Jackson of the American Chamber calls that perception inaccurate.
"The average Korean tariff in manufactured goods and agricultural goods is far higher than that of the United States. So just on the tariff side alone this agreement will bring tremendous preferential access to U.S. companies, to the benefit of U.S. workers in all sectors," said Jackson.
South Korean backers of the deal say their country's consumers will enjoy lower prices on imported food and a more efficient flow of investments both ways. But critics say it will harm South Korean farms and the country's financial industry.
South Korea has said it will not renegotiate the agreement, but it is willing to work with the United States to address concerns in Congress.