The statement comes after US Secretary of State John Kerry called India's National Security Advisor Shivshankar Menon Wednesday to express his "regret" over the situation in a bid to end the standoff between the two countries over the issue.
"Just regretting and completing a formality is not acceptable. We are not happy. The way they have handled this case, their behaviour and attitude... they will have to apologise," Nath told media persons here.
"They should admit that they have committed a mistake and only then will we be satisfied," he added.
Khobragade, India's deputy consul general in New York, was strip-searched, cavity-searched and swabbed for DNA after her arrest in New York last week on charges of visa fraud and under-paying her maid.
The 39-year-old was confined with criminals before being released on a $250,000 bail.
Following the incident, privileges given to the US diplomats in India were pared down, including withdrawal of diplomatic ID cards issued by the Indian government, taking away airport passes and withdrawing extra security barricades outside the US embassy.
--IANS (Posted on 19-12-2013)