BEIJING, Sept.2 -- Negotiators from China, Japan and South Korea called for the conclusion of a comprehensive trilateral free trade agreement by the end of 2015, officials said on Monday.

"The three sides all agreed to accelerate the China-Japan-South Korea FTA negotiations, and we expect to conclude sooner than the RCEP (Regional Comprehensive Economic Partnership)," Assistant Minister of Commerce Wang Shouwen said on the sidelines of the fifth round of China-Japan-South Korea FTA negotiations, which started on Monday.

This round of talks in Beijing is scheduled to wrap up on Friday.

Ministers from 16 Asia-Pacific economies have agreed to finish the RCEP talks by 2015.

"But negotiations are hard to predict. We all have very good intentions to speed up, but we must reach a high-level and comprehensive pact. We will not sacrifice quality for speed, because quality is very important," said Wang, who is also head of the Chinese delegation.

The three countries launched trilateral FTA negotiations in November 2012. The pact is intended to cover trade in goods and services as well as investment and other issues such as intellectual property rights protection.

The pact will forge a common market of 1.5 billion people with a combined GDP of $15 trillion.

Woo Tae-hee, assistant minister for trade at the Ministry of Trade, Industry and Energy of the Republic of Korea, said: "The three countries share a common understanding that the FTA should proceed faster than the RCEP. ... I hope we can make some sensible progress in market access, in liberalization of services and investment. We should look at the bigger picture instead of speaking to small details.

"I also say that we should have a forward-looking attitude toward scope and coverage," Woo said.

Yasumasa Nagamine, vice-minister for international affairs at the Ministry of Foreign Affairs of Japan, said the trilateral FTA will provide a legal framework to promote ties among the three largest economic powers in Asia.

"In Japan, the promotion of the FTA is an important element of the third arrow of so-called Abenomics, the policy package to vitalize the Japanese economy. The trilateral FTA will be an inescapable part of the current economic policy. That is why we are very pragmatic about these negotiations," he said.

Abenomics refers to a set of economic policies initiated by Prime Minister Shinzo Abe.

"We really desire to conclude these FTA negotiations sooner than the RCEP negotiations," Nagamine said.

"At the same time, we should continue to strive for a comprehensive and high-level FTA. Let us be strategic in narrowing the gaps among our stances," he added.

Wang Haifeng, a researcher with the Institute for International Economic Research at the National Development and Reform Commission, said that the key task of the trilateral FTA talks lies in the trade of goods and services, as a separate three-way investment pact took effect on May 17.

"Technically, there is no problem in speeding up the trilateral FTA talks. But the progress is mainly being affected by political factors in Japan," he said.

"The trilateral FTA will bring greater benefits to Japan than its other FTAs while boosting the country's domestic economic restructuring, and it is thus of great significance," Wang said.