New Delhi: US President Barack Obama has written to outgoing Prime Minister Manmohan Singh, applauding his "boldness and vision" in strengthening the bilateral strategic ties "that will have long-lasting impact" besides his resolve to reach out to Pakistan.
The US President also lauded Singh for his efforts to lift millions out of poverty and position India as a global leader.
Obama had also called up Singh last week to say he will miss working with him on a "day-to-day" basis.
"While it was a pleasure to talk to you on the phone, I wanted to respond to your thoughtful letter and put in writing my deep appreciation for your remarkable two terms in office," the US President said in the letter, which was in response to Singh`s farewell letter to him.
Singh resigned on May 17, a day after BJP-led NDA got landslide majority in the Lok Sabha elections. Obama had called him hours later.
"With boldness and vision, during your ten years in office, you challenged our two nations to deepen our defense ties, engage in civil nuclear commerce, expand trade, and collaborate on clean energy technology while working through our differences," Obama wrote to Singh.
"I have tremendous gratitude for the critical role you have played in defining and expanding the strategic partnership between India and the United States," he said.
The US leader told Singh that his leadership helped "strengthen a strategic relationship that will have a long-lasting impact on our citizens and is already making the world a safer, more prosperous place."