Katyayani Shankar Bajpai – a career diplomat who had the unique distinction of being the only person to serve as India’s envoy to the US, China and Pakistan, and became a mentor to several generations of diplomats – has died of Covid-19. He was 92.

Bajpai’s family had a long association with diplomacy – his father Girija Shankar Bajpai was appointed the first secretary general of the external affairs ministry and his brothers Uma Shankar and Durga Shankar too were diplomats – and he was highly regarded for his advocacy of better ties with the US over the decades, with some saying he was ahead of his times in this area.

He joined the Indian Foreign Service (IFS) in 1952 after being educated in Washington, Oxford and Geneva and went on to serve in key positions within the country and around the world. After retiring, he moved effortlessly into the world of academics and became known as a strategist and columnist.

External affairs minister S Jaishankar was among those who counted Bajpai as a mentor. He tweeted shortly after his death on Sunday: “Deeply grieved at the passing away of Amb. Shankar Bajpai, mentor and friend. Will be missed by so many of us.”

Bajpai played a key role in a long string of events during his distinguished career, from being part of prime minister Lal Bahadur Shashtri’s delegation to Tashkent, Uzbekistan, for talks with Pakistan brokered by the Soviet Union that ended the 1965 war, to acting as India’s representative to Sikkim during 1970-74 and assisting in its integration with the Indian union, and serving as the envoy to the US during a groundbreaking visit by prime minister Rajiv Gandhi.

A statement issued by his family said: “Bajpai was a man for many seasons. He could quote poetry classics from memory, was widely and eclectically read, was an avid film buff, but above all was known for his culinary skills and as a consummate host.”

Former ambassador Rajiv Bhatia, distinguished fellow for foreign policy studies at Gateway House, remembered Bajpai as a “very profound and sober man and accomplished diplomat”.

“He was the only diplomat to have served as the envoy to China, Pakistan and the US, and at times when the relationship with each was very complex and complicated, and India was managing three most challenging relationships,” Bhatia said.

“He was also a confidant of prime minister Indira Gandhi and was known as a legendary host during his stint in Washington,” he added.

Bajpai was India’s envoy to the US when prime minister Rajiv Gandhi made his first visit to Washington in 1985, during which he addressed a joint session of the Congress. He also played an important role for prime minister Indira Gandhi’s visit to the US in 1982, during which she interacted with president Ronald Reagan.

As a young diplomat, he served as a political officer in Pakistan during the 1965 war. In 1966, he accompanied prime minister Lal Bahadur Shastri to Tashkent for the summit with Pakistani president Ayub Khan.

Over the years, he also had postings in Bonn, Ankara, Bern, San Francisco and the Netherlands, and his stints in New Delhi saw him focusing on Arab affairs, the UN and disarmament.

After retiring from government service in 1986, Bajpai transitioned to academic life in many universities, including the University of California, Los Angeles, during 1987-88, and was a visiting professor at the University of California, Berkeley, during 1989-92.

He went on to become the first professor of non-Western studies at Brandeis University during 1992-93 and a visiting fellow at the Center for International Security and Cooperation, Stanford University, in 2002.

Besides creating the think tank Delhi Policy Group in 1994, Bajpai served as chairman of the National Security Advisory Board during 2008-10 and was informally consulted by the government on several issues, particularly relations with the US. He was also involved in “track two” interactions with the US and Pakistan.

He remained engaged with India’s foreign policy and governance, and at the time of his death was working on a biography of his father and his own memoirs. Bajpai is survived by his wife Meera Bajpai and two sons Dharma and Jayanti Bajpai.