Chief negotiators for the Trans-Pacific Partnership opened a meeting Wednesday to thrash out thorny issues in a bid to streamline the talks for a deal by the end of the year.

The negotiators from Japan, the U.S. and 10 other Pacific Rim countries have gathered in Washington for four days of talks to prepare for a special leaders' summit on the free trade pact next month in Indonesia.

The chief negotiators discussed five topics on the first day and ordered subcommittees to sort out issues that need to be settled before next month's summit, a Japanese delegate said, without elaborating on the topics. The 12 countries aim to reach a basic agreement at the summit in Indonesia for the creation of one of the world's largest free trade zones covering about a third of world trade. The meeting of chief negotiators is running in parallel with a working group session on tariff elimination scheduled for Friday to Monday in Washington.