The leaders of South Korea and the United States agreed to try and finalize a long-stalled free trade deal ahead of a summit of major economies set for next week, the office of South Korea's president said Tuesday.

Seoul and Washington negotiated the landmark agreement to slash tariffs and other barriers to trade in April 2007 and signed it three months later, but the deal has gone nowhere since.

Changes in government in both countries, the global economic slump and demands by the United States that South Korea make concessions on trade in autos and beef have left it unratified by legislators.

President Barack Obama and South Korean President Lee Myung-bak vowed in June to try and resolve differences by the time they meet at the Group of 20 summit of leading rich and emerging countries in Seoul, which takes place Nov. 11-12.

South Korean Trade Minister Kim Jong-hoon and U.S Trade Representative Ron Kirk met last week in the U.S. in a bid to make progress.

In a telephone conversation Tuesday morning, Lee and Obama agreed to make efforts to finalize the deal before the G-20 summit to promote free trade internationally and upgrade the South Korea-U.S. alliance, Lee's office said in a brief statement.

The U.S. says that the deal cannot go forward without addressing South Korea's overwhelming surplus in auto trade and a further loosening of restrictions on imports of American beef. Seoul has resisted any formal renegotiation of the deal, but has said it is willing to discuss U.S. concerns.

Obama said in June that he wanted the deal with Seoul wrapped up so he can submit it to Congress for approval within a "few months" after his visit to Seoul for the G-20 summit. South Korea's National Assembly must also ratify the agreement for it to take effect.

Bilateral trade between South Korea and the U.S. totaled $66.7 billion in 2009, down sharply from $84.7 billion in 2008 as global commerce suffered during the economic downturn.

Efforts to achieve a breakthrough on the South Korea-U.S. deal come as Seoul and the European Union signed a free trade agreement last month in Brussels and are aiming to see it take effect in July next year.

The 27-member European Union is South Korea's second-largest trading partner after China. The EU is the largest foreign investor in the Northeast Asian country.