The use of discretion by ministers in investment needed to be withdrawn and left to market mechanisms, while the world can expect a bigger and cleaner Indian economy in the coming years, Finance Minister Arun Jaitley said on Tuesday.

Addressing a gathering in New York at Columbia University, he said that when the NDA government came to power in 2014, global investors had lost confidence in India due to rising corruption and scandals.A

Moreover, foreign direct investment (FDI) faced hurdles as the "doors were too narrow", the approval mechanism was slow and tax legislations unclear, he said.

"It was quite challenging to convince investors all over the world," he added.

The rise of corruption was mainly because of the "extraordinary discretion" vested with the government.

Earlier, he said here that the Indian government has been able to change domestic public opinion in favour of inviting foreign investment into sectors of production that were earlier considered out of bounds both for ideological as well as security reasons.

"We have been able to invest FDI in almost every sector of the economy," Jaitley said on Monday night at an investors roundtable jointly organised by the Confederation of Indian Industry and the US-India Business Council.

"Areas that were earlier considered sacrosanct, like defence manufacturing, we have been able to convince public opinion that it is better to invite foreign expertise to set up manufacturing in India," he said.

"Suddenly we find a lot of joint ventures coming up (with foreign firms) for defence investment."

Jaitley is on a week-long official visit to the US during which he will attend the annual meetings of the World Bank and the International Monetary Fund to be held in Washington.