One of India's most powerful politicians has returned to work after undergoing surgery in the United States for an undisclosed illness.

Sonia Gandhi, the leader of India's ruling Congress Party, presided over an election meeting Thursday, nearly six weeks after leaving the country for medical treatment.

Congress Party officials said the 64-year-old looked fit and healthy.

Gandhi had appointed a four-member group to run the political party in her absence. The group included her son Rahul, who is widely viewed as a likely future prime minister.

Born in Italy, Gandhi is the leading figure of a family that has ruled India for most of the period since it won independence from Britain.

She is the widow of assassinated former Prime Minister Rajiv Gandhi. Her mother-in-law, Indira Gandhi, was also assassinated — while serving as prime minister in 1984. And Indira Gandhi's father, Jawaharlal Nehru, was India's first prime minister.

The Nehru-Gandhi dynasty has no family ties to independence leader Mahatma Gandhi.