Influential American Senator Chuck Grassley has opposed the nomination of Eric Garcetti as the US envoy to India because of "serious allegations" of sexual harassment by one of his staffers and urged his senatorial colleagues to do the same.

Grassley's remarks on the Senate floor on Tuesday comes amidst the White House intensifying its efforts to have Garcetti confirmed as the US Ambassador to India, a strategic position that has remained vacant for nearly two years now.