The United States has apologized and expressed deep regret for an "unfortunate" comment made by an American diplomat in India.

Maureen Chao, the vice consul of the U.S. consulate in Chennai, India, was speaking to students at a study-abroad orientation program last week at a university in the capital of the southern-most Indian state of Tamil Nadu, when she recounted her own experiences as a study-abroad student in India two decades ago.

"Some 20 years ago, I was a student like you and had an opportunity to do a semester abroad," Chao told the students, India's NDTV reported. "I chose to come to India, fascinated by the culture and religion."

"I traveled across villages to understand the culture better. I was amazed at the graciousness and friendliness of the people," she continued, before describing a long train journey, during which her remarks went -- so to speak -- off the rails.

"I was on a 24-hour train trip from Delhi to Orissa," the eastern Indian state, Chao continued, according to Agence-France Press. "But, after 72 hours, the train still did not reach the destination ... and my skin became dirty and dark like the Tamilians."

The U.S. consulate soon posted a statement of apology on its website:

"During the speech Ms. Chao made an inappropriate comment," the statement, posted Saturday, read. "Ms. Chao deeply regrets if her unfortunate remarks offended anyone, as that was certainly not her intent."