"India's decision of not joining the Regional Comprehensive Economic Partnership (RCEP) is unfortunate and ill-advised. It is in India's strategic and economic interests to be a part of the process of Asia-Pacific integration.

"Withdrawal has negated years of persuasive negotiations for India to be accepted as part of RCEP. We could have negotiated safeguards to protect our interests. Keeping out of the RCEP is a backward leap," said Sharma, who was Commerce Minister in the UPA government.

Sharma's statement comes after former Union Finance Minister P. Chidambaram criticised the Modi's government stand on RCEP but said that he will reserve his decision till the Congress takes official position on the issue.

Chidambaram had also expressed his dismay over the speech by Foreign Minister S. Jaishankar on Monday, where he railed against trade agreements and praised the virtues of protectionism.

"Mr Jaishankar is speaking in the language and in the words that I heard in the 1970s and 1980s," Chidambaram said.

"There are pros and cons to India joining the RCEP. But the debate has never taken place in Parliament or among the people or involving the opposition parties. It is another bad example of a centralised decision-making unacceptable in a democracy," he added.

However, the Congress had raised concern over joining the RCEP, set to become the  world's largest trading body of 15 nations in the Asia-Pacific region.

After eight years of hard negotiations, the ASEAN nations (comprising Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam) signed the trade pact with five FTA partners -- China, Japan, South Korea,  Australia and New Zealand -- on Sunday.