NEW DELHI: India’s first national security advisor Brajesh Mishra, who played an instrumental role in shaping the country’s foreign policy, has died, officials said on Saturday.

Mishra, who died late Friday, served as national security advisor and principal secretary to former Indian prime minister Atal Behari Vajpayee during his government from 1998 to 2004, acting as troubleshooter.

Prime Minister Manmohan Singh paid tribute to Mishra, calling him “one of the most able and influential public servants of his generation” who brought “a sense of India’s destiny and place in global affairs”.

The death of Mishra came a day before his 84th birthday.

Officials gave no cause of death but Indian media reports said Mishra had been suffering from a heart ailment.

Mishra, a career diplomat, sought to fashion a broad vision of India’s foreign policy under Vajpayee, who was prime minister of the Hindu nationalist Bharatiya Janata Party, now sitting in opposition.

He was closely involved in the planning for India’s 1998 nuclear tests that effectively made India a nuclear-weapons power, pushed for stronger relations with the United States and sought warmer ties with rival Pakistan and China.

The underground nuclear tests conducted in the Indian desert won domestic support and fired up national pride but sparked an international outcry and trade sanctions along with tit-for-tat nuclear explosions by Pakistan.

“He will be remembered for his masterly handling of the aftermath of the (Indian) nuclear tests in 1998 and for guiding Vajpayee’s peace initiatives in the neighbourhood,” Singh said in a statement.

New Delhi’s nuclear isolation lasted until 2008 when the United States struck a deal with India giving it access to civilian nuclear technology.

During his diplomatic career, Mishra served as an ambassador and as India’s permanent representative to the United Nations.