SEOUL, South Korea (AP) - The United States and South Korea can still wrap up a free trade agreement, although tough issues remain and time is running short, Washington's chief negotiator said Monday.
''Our challenges are real but they are not insurmountable,'' Assistant U.S. Trade Representative Wendy Cutler told reporters after U.S. and South Korean officials opened a fresh round of talks in Seoul, their sixth since negotiations were formally launched last June.
Outside the venue - a swank, hilltop hotel - thousands of riot police stood guard against street protests that have dogged the previous two rounds held in South Korea.
Demonstrations Monday near the site were small. In one, less than 10 protesters including farmers and workers engaged in a minor scuffle with police. In another, lawmakers from a small opposition party went on a hunger strike. Bigger protests were planned Tuesday.
In the largest, about 100 mostly college students held a peaceful, candlelight protest Monday evening against the talks as dozens of riot police stood by.
''Our remaining time for these negotiations is short if we are to take advantage of the window of opportunity provided by the current trade promotion authority,'' she said.
Under U.S. President George W. Bush's special ''fast-track'' authority, Bush can submit a deal to Congress for a straight up-or-down vote without amendments until the end of June.
But any agreement would have to go to Washington by the end of March because lawmakers would need to review the agreement before a vote. South Korea's legislature would also have to approve the pact.
A successful deal would slash tariffs and other barriers on a wide range of goods and services from the two nations, which do $72 billion worth of business a year. South Korea, the world's 10th-largest economy, is already the United States' seventh-biggest trading partner.
The latest round in the United States last month failed to bridge numerous gaps, including Seoul's request for Washington to change its antidumping laws.
Cutler said Monday that she and her South Korean counterpart Kim Jong-hoon would themselves be taking up the most contentious outstanding issues - trade remedies, automobiles and pharmaceuticals-medical devices - this week to try and reach a breakthrough.
She also said an ongoing beef dispute between the two countries was a hurdle and must be resolved even though it's not technically part of the free trade negotiations.
''A resolution of this issue is also critical if the FTA is to become a reality,'' she said.
South Korea, formerly the third-largest market for U.S. beef, last year allowed a limited resumption of American beef imports following a ban of nearly three years after mad cow disease was discovered in the United States.
But all three shipments that have so far arrived were turned away after authorities discovered banned bone fragments, which authorities fear could harbor the disease, known formally as bovine spongiform encephalopathy.
''They're still miles apart on some of the most sensitive issues,'' Jeff Vogt, a global economic policy specialist with the U.S. labor group AFL-CIO, said before joining the candlelight protest.
''There are so many things, like autos or beef or trade remedies that any one of those, if they're not resolved, could mean disaster for USTR,'' he said.
The proposed free trade agreement has drawn fierce resistance from South Korean labor, agriculture and social groups, as well as the film industry, who say free trade threatens their livelihoods.
The government late last year vowed ''zero tolerance'' for violent protests, threatening to take all measures available including criminal punishment and claims for compensation.
The Seoul Metropolitan Police Agency was mobilizing about 15,000 riot police during the weeklong talks.