NEW DELHI -- Atal Bihari Vajpayee, a three-time prime minister and stalwart of India's ruling Bharatiya Janata Party, died on Thursday. He was 93.
Prime Minister Narendra Modi called Vajpayee's death a "personal and irreplaceable loss."
"It was due to the perseverance and struggles of Atal Ji that the BJP was built brick by brick," Modi tweeted.
Vajpayee was admitted to the All India Institute of Medical Sciences in New Delhi nine weeks ago following a kidney tract infection and chest congestion.
"Despite the best efforts, we have lost him today," the institute said.
Vajpayee was a charismatic leader and orator. The former prime minister was admired at home and abroad for his statesmanship as well as his efforts to improve ties with Pakistan, the neighbor and rival with which India has held a longstanding dispute over the northern Kashmir territory.
But Vajpayee also oversaw a series of nuclear tests in May 1998 that led to economic sanctions from the U.S. India's nuclear arsenal is meant as a deterrent against Pakistan.
Following a visit to Kashmir on the Indian side, Vajpayee in 2003 had said guns cannot solve any problem, but that brotherhood can.
"Issues can be resolved if we move forward guided by the three principles of insaniyat [humanism], jamhooriyat [democracy] and Kashmiriyat [Kashmir's age-old legacy of Hindu-Muslim amity]," he said.
Modi, in his address to the nation Wednesday on India's Independence Day, said he would continue to follow Vajpayee's approach toward the Kashmir issue.
"The path shown by [Vajpayee] is the right one," Modi said. "We do not want to move on the road of bullets and abuses. We want to move ahead with love and affection with the Kashmiri people."
Vajpayee, looking to foster better ties between the people of both nations, initiated a bus service between the Indian capital and the Pakistani city of Lahore. He traveled by the bus to the neighboring country when the service was inaugurated in February 1999, and was received by Nawaz Sharif, his Pakistani counterpart at the time.
Vajpayee served as the first president of the right-wing BJP, which formed in 1980 and has ideological links with the Hindu nationalist Rashtriya Swayamsevak Sangh, or National Volunteers Organization. Viewed as a moderate face of the party, Vajpayee won allies for the BJP and helped it emerge as a strong political force in 1990s.
In 1996, his first stint as prime minister of a BJP government lasted only 13 days after failing to secure a majority.
Vajpayee returned to the post in 1998, when his party led a National Democratic Alliance government. But he quit in just over a year, after a key ally of the ruling coalition withdrew support.
His third outing, from 1999 to 2004, saw Vajpayee complete a full five-year term, the first prime minister to do so outside of the Indian National Congress, which is currently the main opposition party.
The bachelor and noted poet was conferred India's highest civilian honor, the Bharat Ratna, in 2015. He was first elected to Parliament in 1957 as a leader of the Bharatiya Jana Sangh, a Hindu nationalist party that was the progenitor of the BJP.
Vajpayee suffered a stroke nearly a decade ago that reportedly weakened his cognitive abilities, and he subsequently developed dementia. He gradually withdrew from public life and remained confined to his residence.