"Whatever else may be believed about Modi, there is universal agreement that he is a decisive leader," writes Ashley J. Tellis, Senior Associate South Asia Programme at Carnegie Endowment for International Peace, a leading Washington think tank
"In many ways, Modi, with his natural assertiveness, may be even better positioned than (former prime minister Atal Bihari) Vajpayee to rebuild the bilateral relationship," he wrote in an article titled "Productive but Joyless? Narendra Modi and US-India Relations."
Tellis also suggested that denial of a US visa to Modi for his alleged role in the 2002 Gujarat riots may cloud India-US relations.
"Obviously, engagement will not come easily because of the uncomfortable fact that Washington and Modi managed to start out on the wrong foot," he wrote.
"The complications attending Modi's personal history are likely to affect the future trajectory of US-Indian relations in unhelpful ways."
But "even though Modi's personal feelings toward Washington are not particularly warm today, he is not likely to go out of his way to spite the United States out of personal pique," he wrote.
"If both sides can avoid stepping on each other's toes, especially in South Asia - an arena in which Modi will be fiercely protective of India's prerogatives - the United States could find itself in a potentially productive bilateral relationship with India," Tellis wrote.
"Precisely because such eventualities represent the most serious threat to US interests in South Asia today, the Obama administration ought to reach out publicly and generously to Modi as soon as it becomes clear that the Indian nation has chosen him as its next prime minister," he wrote.
"A congratulatory call from Obama to Modi followed by a visit to India by a US cabinet member or higher-ranking official would go a long way," he suggested.
"These overtures will not make up for the lost opportunity to engage Modi while he climbed the national stage or efface his accumulated grievances against Washington overnight," Tellis wrote.
"But they would be the necessary first step toward developing a relationship with a leader who will govern India for the next five years," he suggested.