The United States and South Korea signed a free trade agreement Saturday that could become Washington's biggest deal since the 1993 North American Free Trade Agreement.

The free trade pact still needs final approval from U.S. and South Korean lawmakers.

U.S. Trade Representative Susan Schwab attended a signing ceremony today in Washington with South Korea's Trade Minister Kim Hyun-chong. She said today is a "great day for international trade."

President Bush also issued a statement welcoming the signing of the agreement. Mr. Bush said the deal would generate exports for U.S. farmers, ranchers, manufacturers and service suppliers. He also urged Congress to ratify the pact.

The trade deal faces considerable opposition in the U.S. Congress, mainly by majority Democratic Party lawmakers. They argue that the deal could make America less competitive.

Large protests have also been held in South Korea by automaker unions and farmers, who fear the deal will put their jobs at risk.

The trade deal was signed today, just hours before President Bush's so-called "fast track" trade authority was set to expire. That authority allows the Bush administration to negotiate trade pacts that cannot be amended by Congress. Lawmakers can only accept or reject the entire pact.

South Korea and the United States completed the trade pact in April, after 10 months of negotiations. But, the two sides were forced to re-negotiate labor and environmental provisions following requests from Democrats in the U.S. Congress.

On Friday, Seoul and Washington agreed to final changes to the trade agreement which includes new U.S. labor and environmental standards.

Some information for this report provided by AFP and Reuters.