A fresh round of negotiations for a three-way free trade agreement with Japan and China began in Seoul on Tuesday with the countries expected to focus on setting the overall level of market liberalization.

The fourth round of negotiations, to continue until Friday, comes a little over two months after the last session in Tokyo, in which the three countries made what South Korean officials have called minor but significant progress in setting the overall guidelines for negotiations, especially in the area of market opening for products.

The trilateral agreement, if realized, will create one of the world's largest markets as the three countries jointly account for 20 percent of the global gross domestic product and 17.5 percent of global trade.

South Korea's Trade Minister Yoon Sang-jick, however, said a major breakthrough was unlikely to emerge from this week's FTA talks.

"Negotiations do not always go smoothly. In certain cases, (the countries) must engage in a tug of war," Yoon told reporters on Monday.

"It does not mean negotiations are not moving forward just because there is no (visible) progress. It rather means the negotiations are moving toward an end," he added.

Officials have expected stumbling blocks in the negotiations, launched a year earlier in Seoul, as farmers in South Korea and Japan strongly oppose free trade deals over concerns of cheap farm products flooding into their markets. The same issue is believed to have prevented a resumption of negotiations for a South Korea-Japan bilateral FTA, suspended since 2004.

South Korea and China, too, are engaged in separate negotiations for a bilateral FTA  whose 10th round of talks is set for later in the month. (Yonhap)