South Korea and the United States made progress in three of the most sensitive issues in their new round of free trade talks, Assistant U.S. Trade Representative Wendy Cutler said on Wednesday.

In an interview with Yonhap News, Cutler confirmed that the progress made on the contentious areas of antidumping laws, automobiles and pharmaceuticals has been conducted at informal meetings with her South Korean counterpart, Ambassador Kim Jong-hoon.

However, Cutler declined to elaborate further on the progress, stating simply, "My mood is upbeat and I feel we can do this."

South Korea and the U.S. started the sixth round of talks on Monday after having failed to yield any breakthroughs in the previous five rounds which began last June.

Analysts believe that the amount of progress made in this week's talks will determine whether the much-touted free trade deal between the two countries can be clinched in time.

Both sides have been under tight pressure to submit an agreement by April 2 for an official 90-day review by the U.S. Congress for a simple yea-or-nay vote. U.S. President George W. Bush's "fast-track" trade promotion authority expires on July 1.

Cutler, who described this week's negotiations as "very intensive" and conducted "with a new urgency," said the two sides will meet again in February.

"Though there is no formal announcement yet, I think it's safe to say on Friday we will be announcing another round. But beyond that, it's unclear," Cutler said.

"With respect to the number of rounds we hold, I think we will see a lot of high-level contact between now and the next round," the chief negotiator said. Last week, South Korea said in a statement that the two sides have "tentatively" scheduled a seventh round in the U.S. next month.

Cutler also indicated South Korean Trade Minister Kim Hyun-chong and Deputy U.S. Trade Representative Karan Bhatia may hold more meetings between the sixth and the next round. Last week, Kim and Bhatia held a three-day meeting in Hawaii, South Korean officials said.

"There needs to be a lot of contact between Ambassador Kim and me and people senior to us between rounds if this FTA is going to happen," she said.

To narrow differences in the three sensitives areas, the two sides suspended formal "working-level" negotiations during the sixth round and Cutler said she is spending "a lot of time" with her South Korean counterpart.

Cutler denied reports about a so-called "big deal" during the top-level discussions on antidumping, auto and drugs.

However, she stated she wants to "move forward in all areas as far as we can get and both sides will look at the package in the end."

Still, Cutler said she isn't optimistic about any breakthroughs that both sides will publicly announce at the end of this week.

"But, that does not mean the progress hasn't been made. It means that we aren't prepared to announce anything yet. And that's very typical for trade negotiations," she said, adding more progress has been made in "less sensitive areas" such as tariff phase-out in industrial goods and competition.

Rice has not been officially discussed yet, as South Korea wants to exclude the staple from the deal. Yet Cutler insisted that it will be on the negotiating table at some point.

However, "It's unclear whether they will get to discuss the rice issue this week," she said.

South Korea is the U.S.' seventh-largest trading partner with two-way trade totaling $74 billion last year. The U.S.is also South Korea's second-largest export market, taking 17 per cent of its total shipments. If successful, an agreement with South Korea would be the U.S.' largest commercial pact since the North American Free Trade Agreement in 1994.