"Negotiations have just concluded. They have been successful," said Peter Power, the EU executive body's spokesman on trade issues.

"However we have made it clear that for these negotiations to reach their absolute potential, the Korean delegation needs to come with a somewhat more ambitious offer for the next round of negotiations," he said.

Asia's third largest economy and the world's biggest trading bloc began talks on a free trade area in May.

The Commission said the two sides had discussed issues including trade in goods, services and investment, intellectual property rights, competition, and government procurement, as well as regulatory and institutional questions.

"Across those range of topics, there is always scope to achieve more and to achieve greater progress. That is what we are aiming for in September but we have made a good start," Power said.

The EU was South Korea's second largest trading partner after China last year, with trade reaching 78.56 billion dollars. It is the biggest single foreign investor, committing 4.97 billion dollars last year alone.

At the first round in Seoul both sides agreed in principle to scrap about 95 percent of each other's tariffs on merchandise. South Korea's average tariff is 11.2 percent compared to the EU's 4.2 percent.