The US has no plans to drop the criminal charges against Indian diplomat Devyani Khobragade who has been accused of visa fraud, according to the PressTrust of India.

Khobragade was arrested in New York earlier this month before beinggranted bail. Sources said that more evidence is being collected against her to present before January 31, the deadline for the equivalent of a chargesheet to be presented in court.

In Delhi, the US ambassador Nancy Powell said today in a statement, "I join Secretary Kerry in expressing our regret for the circumstances of the consular officer's arrest, but we believe that we can look forward to continuing to expand our bilateral relations."

The case has forged a huge diplomatic dispute between the two countries. New

Delhi, which wants Washington to drop the case and offer an apology, has retaliated by drastically pruning the privileges extended to US consular staff in India.

Khobragade, 39, who was India's deputy consul general at its mission in New York, has been accused by the US of underpaying and overworking her housekeeper, an Indian named Sangeeta Richards. The US says the diplomat lied in a visa application about Ms Richards' salary.

Khobragade's lawyer recently claimed that the US misconstrued the contentious visa application by interpreting Khobragade's salary as that of her housekeeper's. The US has also refuted that charge.

India is trying to secure full diplomatic immunity for Khobragade by shifting her to its UN mission in New York, although such a move needs the US State Department approval.