Former Indian Prime Minister Atal Bihari Vajpayee. File picture: Sebastian John/AP Photo.

New Delhi - Former Indian Prime Minister Atal Bihari Vajpayee passed away at a hospital in New Delhi on Thursday after prolonged illness. He was 93.

Vajpayee was among India's most popular politicians and a founding leader of the ruling Hindu nationalist Bharatiya Janata Party. He retired from active politics in 2005.

Vajpayee was admitted to the All India Institute of Medical Sciences hospital on June 11, suffering from a kidney tract infection and chest congestion.

"Despite the best of efforts, we have lost him today. We join the nation in deeply mourning this great loss," a statement from the hospital said.

Vajpayee's condition turned critical starting Wednesday and he was put on a life support system, prompting visits to the hospital by top leaders, including Premier Narendra Modi.

Vajpayee served three times as prime minister, first for 13 days in 1996, for several months between 1998 and 1999, and then a full-term from 1999 to 2004.

The BJP patriarch had been suffering from ill health in the past years and remained confined to his home. He suffered a stroke in 2009 and was also hospitalized that year with a serious respiratory infection.