The world's biggest trade deal is likely to move forward without India, as the South-Asian country has decided not to join the Regional Comprehensive Economic Partnership (RCEP) agreement, sources in the government said.

The Regional Comprehensive Economic Partnership (RCEP) includes 30 per cent of global GDP and half of the world's people.

Objections by India dashed hopes of signing the deal at this weekend's Association of Southeast Asian Nations (ASEAN) summit in Bangkok, after seven years of gruelling negotiations.

India had raised concerns about market access, fearing its domestic industries could be hard hit if the country is flooded by cheap Made-in-China goods.  The other members have agreed on the text of the draft agreement, aiming for deal to be signed next year.  

"It is the 15 participating countries that have decided to move forward first," China's deputy foreign minister Le Yucheng told reporters Monday.  "Whenever India is ready, it is welcome to get on board," he said.

RCEP includes the 10-nation ASEAN bloc along with China, India, Japan, South Korea, Australia and New Zealand.

The deal has gained new traction amid a bruising US-China trade war that experts fear could drag global growth.  

Prime Minister Narendra Modi, who is under domestic pressure to pull out of RCEP, told the Bangkok Post over the weekend that it would create "unsustainable trade deficits". Indian unions have staged protests calling for more of a say in the final deal.

Australian Prime Minister Scott Morrison said Monday "the text of RCEP is done", echoing the deal's open-door policy.  "It is important to have India in and that is certainly our preference," he told reporters in Bangkok.

Even without India in the mix, RCEP will be the world's largest trade pact.  A diplomatic source in Bangkok told AFP India's inclusion in the deal is important to offset Beijing, the world's second-biggest economy.

"RCEP has better strategic value if it includes India. Without India, there is no balance," the diplomat told AFP.