Kenneth Juster's comments came in the backdrop of reports that the Trump administration was considering tightening H-1B visa rules that could lead to the deportation of about 750,000 Indians.
The US government, however, has denied these reports.
"We have 4 million Indian-Americans in the US. So we are a country of immigrants and that's what helped drive our economy and growth and made us where we are and that's not going to change," he said while delivering his first policy speech since taking over as ambassador.
Mr Juster added that the US is looking at how various categories of visas are working and whether they need refinements.
"We take more immigrants than any other country in the world," he added.
According to the National Foundation for American Policy, more than half of privately-held companies worth $1 billion or more in the US had at least one immigrant founder, with many entering America on an H-1B visa, including the CEOs of both Microsoft and Google.
Meanwhile, External Affairs Ministry Spokesperson Raveesh Kumar said India remains engaged with the Trump administration as well as the Congress on the H-1B visa issue.
"We have shared our concerns to the US side. We have told them that this is a mutually beneficial partnership which should be nurtured and supported," he said.
Mr Kumar said India continued to closely monitor the developments relating to the issue, adding that alarmist projections on possible difficulties to Indian professionals have been laid to rest by the Department of Homeland Security in the US.