However, in a sudden u-turn in February, the US signalled the end of its boycott of Modi when its ambassador to India Nancy Powell met him in Ahmedabad.
US Officials have since said whoever is elected India's next leader would be welcome to the US.
"We look forward to working with the leaders chosen by the Indian people to advance this important partnership and to set an ambitious agenda," Psaki said.
She refused to comment on the results of the exit polls according to which Modi could be the next Prime Minister.
Meanwhile, a top American expert has said the prospect for a dramatic resuscitation of Indo-US relations under a Modi government in India looks less than promising, which he mainly attributed to visa issue related to him.
"Today, both Modi and the United States are trapped in a catch-22: in understandable pique, Modi has declared that he will never apply for an American visa again - and there is no way to revalidate his now-expired visa if he will not apply anew," said Ashley Tellis, from the Carnegie Endowment for International Peace, a prestigious American think-tank.
