Japan and Indonesia started their fourth round of official negotiations Monday on a bilateral free-trade agreement, with the goal of reaching a basic accord by midyear by accelerating talks.

The delegations are headed by Deputy Foreign Minister Mitoji Yabunaka and former Indonesian Ambassador to Japan Soemadi Brotodiningrat.

The talks, in Tokyo, are scheduled to last five days.

"This is a very important time to demonstrate to the world that our partnership is strong," Yabunaka said in an opening address.

Soemadi said the substance of the FTA is as important as the time frame and called on both sides not to "sacrifice content" by rushing to conclude the negotiations.

The two countries launched the talks last July and want a deal in less than two years.