"India is changing in a way that is significant but not always evident to those who do not see the big picture," he said, addressing the Indian diaspora at the Bharatiya Pravasi Day congregation here.
The country, he added, is "prepared to assume the international role and responsibilities that the world at large expects from a rising India."
Seeking to dispel a sense of pessimism in view of falling growth, Manmohan Singh said the economy would grow at 5 per cent in 2013-14 and it was heading towards better days.
"There is a perception in some quarters outside India that the country is losing its momentum of the past decade. This is also amplified by the political contestation here in India, which are inevitably louder in the election season that is now on the horizon."
"I wish to assure you that there is no reason to despair about our present or worry about our future," the Prime Minister told the audience.
"Our economic fundamentals remain strong. Our savings and investment rates are still over 30 per cent of our GDP and the entrepreneurial spirit in India is very much alive and kicking," he said.
He, however, agreed that more could have been done.
"With greater political support, we could have legislated deeper reform measures - for example, in the financial and insurance sector."
"However, our decisions are already beginning to make an impact and India is re-emerging as an attractive investment destination. I am confident you will see the evidence clearly in the next few months."
The Prime Minister also assured the non-resident Indians of continuous support and assistance in promoting their links with the mother country in every possible way.
"We have also recently launched the Mahatma Gandhi Pravasi Suraksha Yojana to provide social security to Indian workers abroad. The Pravasi Bharatiya Kendra in Delhi will be completed this year. We also intend to start a scheme to assist state governments in establishing Pravasi Bharatiya Bhawans," he said.