Japan and the United States on Friday wrapped up their three-day trade talks on the US-led Trans- Pacific Partnership (TPP) free trade negotiations, recognizing that challenges still lie ahead.

The talks, which covered autos, insurance and non-tariff barriers in nine areas, were held in parallel with the dialogue Japan participated in last month.

The dialogue was under a request by the United States, which seeks to further open up Japan's market through the establishment of unified auto safety standards and other measures.

Head of the Japanese delegation Takeo Mori said that a lot still need to be done before the two countries can reach an agreement, reported local media.

"As we are at the stage of narrowing down issues, we have yet to reach the stage for forging an agreement or finding common ground," Mori was quoted by Japan's Kyodo News as saying.

Wendy Cutler, acting deputy US trade representative, said the bilateral talks were a good start, but both sides still face a great deal of challenges.

Japan and the United States agreed to launch the parallel talks in April, adding they had finished preparatory talks for Japan's participation in the TPP negotiations.

The next round of the bilateral talks has not yet been arranged so far as both sides have to digest what they discussed in the first round, said Kyodo. The next round of TPP negotiations will be held in Brunei from Aug. 22 to 30.