A senior U.S. trade envoy said today that worries in the United States over South Korean trade barriers to U.S. autos continue to block approval of a U.S.-South Korean free trade agreement, according to AP. Deputy U.S. Trade Representative Demetrios Marantis' comments temper President Barack Obama's pledge to strengthen trade ties with South Korea in his State of the Union address on Wednesday and signal a difficult road ahead for congressional ratification of the accord to cut tariffs and remove barriers to goods and services. Marantis, fielding questions after a speech, gave no hint about when the deal would be sent to lawmakers for a vote, saying only that «substance will drive the timing.» When pressed on specific U.S. worries, he mentioned the South Korean auto industry's «unfortunate legacy» and «bad history» of excluding foreign autos. Obama and Congress have faced criticism for not acting on the South Korea deal, which was signed during the George W. Bush administration. The U.S.-South Korean accord is stuck in political limbo amid dissatisfaction in Washington over South Korea's huge surplus in auto trade with the United States. Despite Obama's comments on trade, many Democrats resist free trade deals that they say have contributed to a loss of jobs in the United States and to the weakening of worker rights and the environment in the partner country. The U.S. government says U.S. exports to Korea could rise $10 billion to $11 billion annually because of the accord. Republican Rep. Ileana Ros-Lehtinen chastised Democrats for blocking votes on pending trade deals. She urged Obama «to get off the sidelines and fight for the passage of free trade agreements with Colombia, Panama and South Korea.» Marantis said that exclusion from the competitive Asian market will cost U.S. jobs. He acknowledged, however, that many Americans have soured on the idea that free trade agreements with Asia will help create wealth for U.S. workers. The Obama administration, Marantis said, is working to prepare the U.S.-South Korea trade deal for Congress and is confident that all sides will arrive at a solution. But he said that negotiators must still work through the «very difficult» issue of autos. South Korea has said it is not open to any new negotiations with the United States over the deal. Obama said in his Wednesday night speech that he has set a goal of doubling exports over the next five years. He said that will support 2 million jobs in America. Obama said he will keep pushing to boost relations with foreign trading partners. But reaping the benefits of trade, he said, also means that U.S. partners must «play by the rules.» South Korea's government warns that the United States could lose several hundred thousand jobs if it fails to act and Seoul's trade agreement with the European Union is ratified.