There are several complex issues, including the proposed three-tier system of tariff relaxation and services sector matters, which need intervention at a ministerial level, a senior official said.
"On August 5, all the trade ministers will meet to deliberate on those issues and try to resolve them so that the talks can be concluded on time," the official added.
In the recently-concluded 12th round of negotiations for the mega trade deal - RCEP - in Auckland, a few members raised concerns about the three-tier system proposed by countries, including India, to cut or eliminate taxes on goods.
India has decided to offer greater access to its market for ASEAN countries - with which it has a free trade agreement in place - and has proposed to eliminate duties or tariffs on 80 per cent of items for the 10-nation bloc under this proposed pact.
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Similarly, for Japan and South Korea, it has offered to open up 65 per cent of its product space.
RCEP is a mega trade deal which aims to cover goods, services, investments, economic and technical cooperation, competition and intellectual property rights.
The talks for the pact started in Phnom Penh in November 2012. The 16 countries account for over a quarter of the world's economy, estimated to be more than USD 75 trillion.
India already has FTAs with the ASEAN grouping, Japan and South Korea.
The 16-member bloc RCEP comprises 10 ASEAN members (Brunei, Cambodia, Indonesia, Malaysia, Myanmar, Singapore, Thailand, the Philippines, Laos and Vietnam) and their six FTA partners - India, China, Japan, South Korea, Australia and New Zealand.