Officer Manny Encarnacion was arrested last month while traveling in New Delhi where he was visiting his wife, and he has been barred from leaving that country until the case is resolved.
The New York Police Department said Encarnacion was arrested after Indian authorities discovered three bullets he had accidentally packed in his luggage.
U.S. Rep. Peter King suggested Friday the arrest was payback for last year's arrest of Indian consular official Devyani Khobragade for alleged visa fraud in New York. In a letter, King asked Secretary of State John Kerry to look into the situation. The New York Republican called the arrest "an excessive act by the Indian government."
But Encarnacion's Indian lawyer, Samarjit Pattnaik, said in a statement released Saturday there is no reason to suspect any diplomatic connection in the case.
New York Police Department Deputy Chief Kim Royster said the department was working with the State Department to try to get the charges dropped so Encarnacion could return to the United States.
State Department spokeswoman Marie Harf said she was aware of the reports of the officer's arrest but declined to comment on the specifics of the case because of privacy concerns.
Asked whether the United States is worried whether Americans are potential targets for retribution because of how the Indian diplomat was treated in New York, she responded, "I think we feel like we've moved past this and hope the Indians have as well. ... India is a very close partner."
Encarnacion, 49, joined the NYPD in 2004 and is assigned to a Harlem precinct.
The officer had gone to the department firing range before he left for India and put the bullets in a coat pocket, according to police. He packed the coat for the trip, forgetting the ammo was there, police officials said.
Encarnacion's next court date in India is April 17, U.S. officials said.