Secretary of State John Kerry personally expressed "regret" to the Indian government for last week's arrest of an Indian consular official, in an urgent bid to temper a diplomatic clash which escalated into Wednesday.
The controversy grew as the Indian diplomat, Devyani Khobragade, claimed she was subjected to a cavity search, and New Delhi ramped up its retaliatory measures.
The State Department said Kerry personally called Indian National Security Adviser Shivshankar Menon on Wednesday to discuss the case. The statement said Kerry understands the importance of enforcing U.S. law but "it is also particularly important to Secretary Kerry that foreign diplomats serving in the United States are accorded respect and dignity just as we expect our own diplomats should receive overseas."
The statement added that "in his conversation with National Security Advisor Menon he expressed his regret, as well as his concern that we not allow this unfortunate public issue to hurt our close and vital relationship with India."
According to Indian media, Khobragade has been transferred to India's Permanent Mission in New York, potentially a move to get her diplomatic immunity.
It's unclear how far the gestures might go toward tamping down the rhetoric and retaliation in India. A day earlier, Indian officials removed security barriers from outside the U.S. Embassy in New Delhi -- apparently in protest of Khobragade's treatment. The government continued to strip American diplomats of additional privileges on Wednesday, reportedly freezing the ability of consular staff to import duty-free alcohol and food.
Prime Minister Manmohan Singh described the diplomat's treatment as "deplorable."
Khobragade, India's deputy consul general in New York, was arrested last Thursday outside of her daughter's Manhattan school on charges that she lied on a visa application about how much she paid her housekeeper, an Indian national. Prosecutors say the maid received less than $3 per hour for her work.
But Indian officials said Khobragade's treatment was heavy-handed.
In an email published in India media on Wednesday, Khobragade said she was treated like a common criminal, including with a cavity search -- a detail that had not previously been disclosed.
"I broke down many times as the indignities of repeated handcuffing, stripping and cavity searches, swabbing, in a holdup with common criminals and drug addicts were all being imposed upon me despite my incessant assertions of immunity," she reportedly wrote.
Khobragade was arrested by the U.S. Department of State's diplomatic security team and then handed over to U.S. marshals in New York.
The U.S. Marshals Service confirmed Tuesday that it had strip-searched Khobragade and placed her in a cell with other female defendants. It described the measures as "standard arrestee intake procedures."
Prosecutors say Khobragade claimed on visa application documents she paid her Indian maid $4,500 per month, but that she actually paid her less than $3 per hour. Khobragade has pleaded not guilty and plans to challenge the arrest on grounds of diplomatic immunity.
Marie Harf, U.S. State Department deputy spokeswoman, said Khobragade does not have full diplomatic immunity. Instead, she has consular immunity from the jurisdiction of U.S. courts only with respect to acts performed in the exercise of consular functions.
If convicted, Khobragade faces a maximum sentence of 10 years for visa fraud and five years for making a false declaration.
The fallout from the case was growing. India retaliated against U.S. diplomats with measures that include revoking diplomat ID cards that brought certain privileges, and demanding to know the salaries paid to Indian staff in U.S. Embassy households.
On Wednesday, dozens of people protested outside the U.S. Embassy, saying Khobragade's treatment was an insult to all Indian women.
In New Delhi, the lower house of Parliament had to be temporarily adjourned Wednesday after lawmakers noisily demanded that it adopt a resolution against the United States.
Arun Jaitely, leader of the opposition in the upper house, said the government had to register its "strongest protest" to the U.S. government for the "lack of respect for India." He called for a review of India's relations with the United States, a demand that was vociferously seconded by many lawmakers.
Commerce Minister Anand Sharma said the arrest was a "matter of national outrage." He promised angry lawmakers that the government would make an official statement in Parliament on the incident.
The Associated Press contributed to this report.