SEOUL South Korean President Lee Myung-bak and President Barack Obama have pledged to settle their differences on a free trade deal before next week's G20 summit, Lee's office said on Tuesday.
The two countries are trying to resolve concerns raised by U.S. auto and beef industries that are blocking congressional approval of the pact that some studies said could boost their $78 billion trade by as much as a quarter.
The agreement was signed more than three years ago, and is the largest signed by the United States since the North American Free Trade Agreement (NAFTA) that went into force in 1984.
"The two leaders pledged on a telephone call to work to agree on FTA before the G20 summit as a role model of promoting free trade in the world and upgrading the alliance between the two countries," Lee's office said in a statement.
The White House said on Monday that negotiators would put "maximum effort" to resolve U.S. concerns on autos and beef by the time Obama goes to Seoul. The pair are due to meet on the sidelines of the summit on November 11.
Some U.S. lawmakers have said the deal does not do enough to open South Korea's auto and beef markets. Sales of U.S. autos have lagged behind European and Japanese cars despite imported brands' growing acceptance in the market that is home to the world's number-five carmaker, Hyundai Motor.
South Korean officials have rejected the idea of reworking the deal, saying it already offers a balanced way of expanding bilateral trade that benefits both sides.
Prime Minister Kim Hwang-shik told parliament on Tuesday that the bottom line for South Korea is there cannot be any revision or renegotiation of the deal that has already been signed.
(Reporting by Jack Kim; Editing by Jeremy Laurence and Jonathan Thatcher)