"Congrats, Ken Juster, the new US Ambassador to India!" Vice President Mike Pence said in a tweet after administering the oath of office to him on Monday.
"The ties between the United States and India run deep, and @POTUS & I are confident that with his leadership, integrity & experience, Ken will build an even stronger partnership that will benefit our nation & our people," Pence said.
An old India hand, Juster, 62, is expected to be headed for India soon so as to prepare for and ensure a successful visit of Ivanka Trump to Hyderabad later this month.
Daughter of the US President Donald Trump and his senior presidential advisor, Ivanka will be leading a high-powered delegation of American officials and entrepreneurs to attend the Global Entrepreneur Summit being hosted by India in Hyderabad.
Juster replaces Indian-American Richard Verma as the top American diplomat to India.
The position has been lying vacant since January 20 after Verma resigned from the post after the swearing in of Donald Trump as the 45th President of the US.
His nomination was confirmed by the US Senate unanimously on November 2. Juster founded and served as the US Chair of the US-India High Technology Cooperation Group, and was one of the key architects of the 'Next Steps in Strategic Partnership initiative' between the US and India.
His work related to India played an important role in the transformation of the US-India relationship and helped provide the foundation for the historic civil nuclear agreement between the two countries.
Most recently, Juster had served as the Deputy Assistant to the President for International Economic Affairs and Deputy Director of the National Economic Council.
Juster has also served as the Counsellor (acting) of the State Department from 1992-1993, and deputy and senior adviser to the Deputy Secretary of State from 1989-1992.
In the private sector, he has been a partner at the investment firm Warburg Pincus LLC, Executive Vice President at Salesforce.com, and senior partner at the law firm Arnold & Porter.
He has also served as Chairman of Harvard University's Weatherhead Centre for International Affairs, and as Vice Chairman of The Asia Foundation.
Juster holds a law degree from the Harvard Law School, a masters degree in Public Policy from the John F Kennedy School of Government at Harvard, and a bachelors degree in Government from Harvard College.
During his confirmation hearing in October, Juster told lawmakers that India and the US share common values and a commitment to democracy, pluralism and the rule of law.
"The administration firmly believes that a strong India and a strong US-India relationship are in America's interest. India's role in the Indo-Pacific region and globally will be critical to international security and the economic growth over the course of this century," he said.
"There are many elements of our effort to expand and enhance the strategic partnership between our countries. One key pillar is to deepen defence and security cooperation building on the US recognition of India as a major defense partner," he said.
"Together, our countries seek to ensure freedom of navigation, over flight and commerce and advance a rules-based democratic order throughout the Indo-Pacific region," he said as he vowed to strengthen India-US cooperation on the most pressing challenges to regional security and global peace.