Sonia Gandhi, the leader of India’s Congress Party and widow of former Prime Minister Rajiv Gandhi, will undergo a surgical procedure abroad for an undisclosed medical condition.

“She was recently diagnosed with a medical condition and has been advised surgery,” said Janardhan Dwivedi, a spokesman for Congress.

He added that Gandhi will "likely to be away for two to three weeks".

It is not known where she has gone for surgery. The Press Trust of India reported she departed for the U.S. on Wednesday. There is also controversy over why she is not undergoing treatment in India, which is famous for having top doctors and medical facilities. Some reports speculate that she may need some kind of specialist treatment not yet available in India.

While Gandhi, now 64 years old, holds no official position in government, she is widely regarded as the most powerful politician in the country.

In fact, it was she who nominated Manmohan Singh to the prime minister's post in 2004.

Born in Italy, she is the daughter-in-law of Indira Gandhi, and as such, carries the mantle of the Nehru-Gandhi dynasty that has dominated Indian politics since independence in 1947.

Gandhi’s sudden and unexpected departure comes as the New Delhi government is involved in sensitive peace talks with neighboring Pakistan and faces a raft of corruption charges involving top officials.

During her absence, Gandhi has appointed a four-member team to run Congress Party business. This group includes her son, MP Rahul Gandhi, who is being groomed as a future prime minister.