In a series of tweets, Modi spoke about the benefits of demonetization and said the country has a "historic opportunity" to embrace increased cashless payments.
"I salute the people of India for wholeheartedly participating in this ongoing 'Yagna' against corruption, terrorism & black money," he said.
"Together, we must ensure #IndiaDefeatsBlackMoney. This will empower the poor, neo-middle class, middle class & benefit future generations," Modi added.
He said the decision has several gains for farmers, traders, labourers, "who are the economic backbone of our nation" and "no longer will the progress and prosperity of rural India be curtailed by corruption & black money. Our villages must get their due."
He went on to add, "We also have a historic opportunity to embrace increased cashless payments & integrate latest technology in economic transactions."
The tweets came amid strong attack by Opposition against him over demonetization decision.