• Former Indian Prime Minister Manmohan Singh's passing at the age of 92 triggered an outpouring of condolence messages.
• Narendra Modi, India's current prime minister, called Singh one of India's "most distinguished leaders."
• Singh played a crucial role in opening up India's economy to the world as finance minister in the 1990s and helped strengthen diplomatic ties with the U.S.

Former Indian Prime Minister Manmohan Singh's passing on Tuesday at the age of 92 triggered an outpouring of condolence messages and tributes from political leaders from both sides of the aisle and industry titans.

Prime Minister Narendra Modi called Singh one of India's "most distinguished leaders" in a post on X. Modi's Bharatiya Janata Party defeated Singh's Congress alliance in the 2014 elections and has been in power since.

Singh was a "respected economist," Modi added, who left "a strong imprint" on India's economic policy.

Before he became prime minister in 2004, Singh served as the governor of the Reserve Bank of India in 1982 and as minister of finance in 1991.

As finance minister, he led a series of reforms that deregulated India's economy and opened the country to foreign investment.

Facing an acute balance of payments crisis, then-Prime Minister P.V. Narasimha Rao and Singh liberalized the economy that paved the way for its rapid expansion in the following decades.

"History will forever honour his pivotal role in the transformative 1991 reforms that reshaped India and opened its doors to the world," wrote Gautam Adani, India's second-richest person and chairperson of Indian conglomerate Adani Group.

Singh returned to politics in 2004 when a Congress-led coalition swept the elections, and party leader Sonia Gandhi appointed him prime minister.

Under his tenure between 2004 and 2014, India's gross domestic product initially expanded rapidly, allowing Singh to deploy the new wealth to programs such as the National Rural Employment Guarantee Act, which guaranteed jobs for the poor. 

The later years of Singh's stint as prime minister were, however, marred by sclerotic growth, a stalling of reforms and allegations of corruption against certain members of the government.

Singh played a pivotal role in strengthening India's ties with Washington, visiting the U.S. multiple times as prime minister. In 2006, when U.S. President George W. Bush visited India, Singh managed to broker a deal that gave India access to U.S. nuclear technology.

"Dr. Singh was one of the greatest champions of the U.S.-India strategic partnership, and his work laid the foundation for much of what our countries have accomplished together in the past two decades," wrote the U.S. Department of State on Singh's passing.

Apart from the U.S., Singh also strengthened India's ties with Russia. He was a regular attendee of the India-Russia Annual Summit, which began in 2000, and aims to deepen cooperation between the two countries and among BRIC nations.

Russian Ambassador to India Denis Alipov said on X that "Dr Manmohan Singh's contribution to our bilateral ties was immeasurable."