The pact still has to be ratified by both national assemblies and US negotiators faced criticism at home for failing to win enough concessions from Seoul, notably on agriculture and cars.
Even President Roh Moo-hyun, in a triumphant televised address after the deal was agreed, allowed that his negotiators might have been too successful and he would like to have seen more openness in such heavily protected areas as education, medical services and broadcasting.
"The president remained determined (to push for a deal) with the simple logic that if we open our doors we may succeed or we may fail, but if we do not, we will fail for sure," the JoongAng daily, normally critical of Roh, wrote in an editorial.
Even members of the main opposition Grand National Party (GNP) said they would back passage of the deal through the national assembly for Roh, who is in his last year in office and has a popularity rating of only just over 20 percent.
"The GNP must help and encourage the president until it is ratified," said MP Jun Yeo-ok, whose party is now the biggest in the assembly.
It may be more of a struggle to push it through the US Congress.
The pact on reducing tariffs and other barriers to two-way trade, which already totals more than $70 billion a year, was agreed minutes before the White House ran out of time to agree a pact that Congress could not change, but only accept or reject.
US politicians were quick to attack the agreement, although officials insisted it would give a significant boost to US companies exporting to South Korea.
SENATE BEEF
The chairman of the influential Senate Finance Committee, Max Baucus, threatened to block it until Seoul completely lifted its ban on US beef -- something it has committed to only after 15 years.
US politicians and the auto industry complained that South Korea, a quarter of whose car exports go to the United States but which imports few cars, had failed to open its market enough.
For some, the pact, the largest trade deal Seoul has ever reached, will help nudge its economy away from protection and make it far better able to deal with the longer-term competitive threat of powerful neighbors Japan and China.
Many South Korean analysts and senior officials say the country remains far too dependent on manufacturing to become a truly advanced economy and must develop its service sector.
"It may appear that the United States has agreed to cut tariffs in more sectors, but what South Korea has agreed to do is to make changes to the fundamental social structure," said Song Ki-ho, an attorney and trade law expert.
There were still plenty of critics within South Korea, including the main film industry lobby group that wanted a current limit of Hollywood imports to be tightened.
"We will remember any presidential candidates and MPs who support the ratification of the agreement. We pledge that they will pay a price in the 2007 presidential election and 2008 parliamentary election," the Korea Screen Quota Action Alliance said in a statement.
Small opposition parties were equally angry, including the Democratic Labor Party that is backed by the labor unions that have been a leading force behind large, sometimes violent protests against the agreement during the past nine months of negotiations.
"We'll block the signing of the South Korea-US FTA (free trade agreement) with everything we've got," party spokesman Kim Hyung-tak said. (Reuters)
