The United States has apologised for controversial remarks made by a US diplomat who spoke of "dark and dirty" Indians, calling the comments "inappropriate". US Vice-Consul Maureen Chao told Indian students on Friday that her "skin became dirty and dark like the Tamilians" after a long train journey, according to Indian media -- referring to people from the southern state of Tamil Nadu. During her speech in the Tamil Nadu capital, Chennai, Chao was quoted as saying: "I was on a 24-hour train trip from Delhi to (the eastern Indian state of) Orissa. "But, after 72 hours,