President Park Geun-hye pledged Wednesday to closely cooperate with Japan to forge a trilateral free trade agreement which also involves China.

Park made the comment in a meeting with a delegation of Japanese business leaders at the presidential office.

Her comment came as chief negotiators from the three countries ended two-day talks without a breakthrough.

"We have made headway on some issues, but the talks continued to move slowly," said Kim Hak-do, Seoul's chief negotiator to the talks, the seventh of their kind since the first round in March 2013.

South Korean officials said the countries have been unable to move forward on the issue of market liberalization for products.

"The sides only confirmed their differences on the level of market opening as they again laid out their own principles," a Ministry of Trade, Industry and Energy official said, asking not to be identified.

The three countries have said they will work to conclude the negotiations before the end of next year.

Efforts to move the talks forward included separating working-level talks from a head delegates' meeting, a move aimed at enabling detailed, in-depth discussions at the working level while leaving sensitive and political decisions to chief negotiators.

This week's meeting of chief negotiators followed working-level talks held in Seoul from April 13-17.

Officials from South Korea's trade ministry said the next round of the three-way talks will be held in China in July.

"They will continue to hold in-between sessions followed by working-level talks in the near future," an official said.

The proposed FTA, if signed, will become one of the most significant free trade pacts ever signed in the region as it will link three of Asia's four largest economies.

The three countries are also taking part in negotiations for a separate regional FTA, known as the Regional Comprehensive Economic Partnership, which currently involves 13 other countries, including all 10 member countries of the Association of Southeast Asian Nations.

South Korea and China have concluded separate negotiations for a bilateral FTA, which is expected to be officially signed in the near future.

Seoul and Tokyo have also held four rounds of talks for a bilateral FTA, but the talks have been suspended since the latest round in November 2004. (Yonhap)