Former Indian External Affairs Minister and senior BJP leader Sushma Swaraj passed away on Tuesday night, AIIMS sources said.
She was the foreign minister when India imposed blockade on Nepal in 2015 over dissatisfaction with the newly promulgated Constitution in Nepal.
She was 67.
The senior BJP leader was brought to AIIMS around 9:30pm and was straight away taken to the emergency ward.
AIIMS doctors said she died of a cardiac arrest.
"Deeply shocked to learn of the passing away of Smt. Sushma Swaraj, a senior political leader of India and former External Affairs Minister. Heartfelt condolences and deepest sympathies to the Government and people of India as well as to the bereaved family members," Prime Minister KP Sharma Oli tweeted Wednesday morning. "I fondly recall how intimately she used to call me brother and share feelings of affinity."
"A glorious chapter in Indian politics comes to an end. India grieves the demise of a remarkable leader who devoted her life to public service and bettering lives of the poor. Sushma Swaraj ji was one of her kind, who was a source of inspiration for crores of people," Indian Prime Minister Narendra Modi said in a series of tweets.
Several senior Indian ministers, including Harsh Vardhan, Rajnath Singh, Smriti Irani Prakash Javadekar, reached AIIMS after she was admitted to the hospital.
Swaraj had put out a tweet in the evening congratulating Prime Modi after the Centre's move to revoke special status for Jammu and Kashmir and bifurcate the border state into two Union Territories secured Parliament's approval.
"Narendra Modi ji - Thank you Prime Minister. Thank you very much. I was waiting to see this day in my lifetime," she had said.
Prime Minister Modi, in his tweets, hailed Swaraj as a "prolific orator and outstanding parliamentarian" and said she was admired and revered across party lines.
"She was uncompromising when it came to matters of ideology and interests of the BJP, whose growth she immensely contributed to," Modi said.
"An excellent administrator, Sushma Ji set high standards in every Ministry she handled. She played a key role in bettering India's ties with various nations. As a minister we also saw her compassionate side, helping fellow Indians who were in distress in any part of the world," he said.
"Extremely shocked to hear of the passing of Smt Sushma Swaraj. The country has lost a much loved leader who epitomised dignity, courage & integrity in public life. Ever willing to help others, she will always be remembered for her service to the people of India," President Ram Nath Kovind tweeted.
Defence Minister Rajnath Singh said he was deeply shocked and anguished by the sudden demise of an extremely valued colleague.
External Affairs Minister S Jaishankar said, "Deeply shocked to learn of the passing away of Smt Sushma Swaraj. Difficult to accept this news. The whole nation grieves, the Foreign Ministry even more so."
The Congress condoled her demise.
"We are saddened to hear about the untimely demise of Smt Sushma Swaraj. Our condolences to her family and loved ones," the party said.
"I'm shocked to hear about the demise of Sushma Swaraj Ji, an extraordinary political leader, a gifted orator & an exceptional Parliamentarian, with friendships across party lines. My condolences to her family in this hour of grief. May her soul rest in peace. Om Shanti," Congress leader Rahul Gandhi said on Twitter.
Starting her political career under the Janata Party, Swaraj was elected to the Haryana assembly in 1977 and became a state minister at age 25. She was again elected to the assembly in 1987 when Devi Lal ousted the Congress from power that triggered an electoral cascade which eventually saw the Congress lose power at the Centre in the 1989 Lok Sabha elections.
She came into national limelight because of her ideologically fierce oratory in Lok Sabha, especially during the 1996 trust vote. Her political articulation, drawn from India’s mythological traditions, endeared her to the common man who could grasp her arguments.
Swaraj had a kidney transplant in 2016 and had opted out of contesting Lok Sabha polls earlier this year for health reasons.
She is survived by her husband Swaraj Kaushal and daughter Bansuri.