Reacting to the upgrade, Jaitley told reporters: "It is a belated recognition of all the positive steps taken in the last few years".
On Friday, the government cheered the upgrade as an endorsement of its reforms.
In the wake of India's rating being upgraded by global credit rating agency Moody, Finance Minister Arun Jaitley said it is "encouraging to gain worldwide recognition and not something that's happening in isolation".
The "Baa3" rating was the lowest investment grade - just a notch above "junk" status.
The upgrade is likely to have a positive rub-off effect on equities, rupee, and bonds, industry insiders said.More news: Funding for sports programs at question in new tax bill
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Modi's top colleagues saw it as a further victory for the prime minister after US-based research agency Pew released a survey this week that showed almost nine out of 10 Indians held a favourable opinion of him.
Stating that reforms will foster sustainable growth, Moody's said government is mid-way through a wide-ranging programme of economic and institutional reforms.
"We have been expecting it for a long time and this was long overdue and is very positive for the market", said Sunil Sharma, chief investment officer with Sanctum Wealth Management. He specifically mentioned the roll-out of the monumental tax reform, GST; the Bank Re-Capitalization package, Ease of Doing Business in India, crackdown against black money, Demonetization and other follow-up measures; and reforms in the Foreign Direct Investment (FDI) Policy regime.
The upgrade is a recognition of the reform process in India, particularly in the last 3-4 years, in which structural reforms placed India on a high growth trajectory, he said.
Union Finance Minister Arun Jaitley on Friday termed the upgrade in Moody's ratings as "extremely encouraging" and also asked the detractors to "introspect" their positions.
According to Moody's, though the high Indian debt burden remains a constraint on the country's credit profile, its longer term growth potential is significantly higher than most other Baa-rated sovereigns.