NEW DELHI: The leader of India's ruling party and head of its political dynasty, Sonia Gandhi, is to undergo surgery in the United States and will leave her son jointly in charge, a spokesman said on Thursday.
Gandhi, 64, is to have an operation for an unspecified condition, ruling Congress spokesman Janardhan Dwivedi said, refusing to give further details.
"On the advice of her doctors, she travelled abroad and she is likely to be away for two to three weeks," Dwivedi said, adding that she would have the surgery in two to three days.
Tehelka news magazine said on microblogging site Twitter that Gandhi was admitted on Thursday to New York's Memorial Sloan-Kettering Cancer Center, the world's largest private cancer centre according to the hospital website. According to Tehelka, renowned oncologist Dr Dattatreyudu Nori, director of the cancer centre at the New York Hospital Medical Center of Queens, is attending on Sonia Gandhi.
Italian-born Gandhi is the widow of assassinated former premier Rajiv Gandhi and widely seen as India's most powerful politician, with her key power-broking position as Congress president.
Dwivedi said that in her absence, Gandhi had appointed a four-member group to handle the day-to-day running of the Congress -- including her son Rahul Gandhi, who is tipped as a future prime minister.
In January 2009, current Prime Minister Manmohan Singh underwent heart bypass surgery at the All India Institute of Medical Sciences in New Delhi.
The Nehru-Gandhi dynasty has ruled India for most of is post-independence history, with three members of the family becoming Prime Minister.
Sonia Gandhi holds total sway within the Congress and is credited with crafting the strategies that gave the party back-to-back general election victories in 2004 and 2009.
She will miss the start of a crucial session of parliament for the scandal-plagued government which intends to introduce draft laws on a range of key areas, including corruption, land acquisition and food security.
Gandhi's absence for the opening of the new session on Monday was noted in the Indian media but explained by an apparent "viral infection" she was said to be suffering from.
Dwivedi initially said that Gandhi had already undergone surgery, but he later retracted the statement.
The mother of two arrived in India as the shy bride of Rajiv Gandhi in her early 20s, and was transformed into a sari-clad Indian who now speaks fluent Hindi.
Her years in the Gandhi household, when her autocratic mother-in-law Indira -- slain in 1984 by her Sikh bodyguards -- was premier, gave her an intimate insight into India's turbulent politics.
Rajiv Gandhi became premier in 1984 and was assassinated in 1991 by a suicide bomber.
Sonia Gandhi, who has described herself as "a reluctant politician," took charge of the Congress in 1998, becoming the fifth member of the powerful Nehru-Gandhi dynasty to serve as party chief.
Although she was hailed as the architect of the 2004 election victory, she eschewed calls to become Prime Minister and handed the post to the current incumbent Singh, partly due to concerns about a political backlash over her foreign origins.
The Bharatiya Janata Party, now the main opposition party, had once referred to her as a "foreign doll."