Jacqueline Kennedy, Mohan & Mohini

JK Galbraith, the noted economist served as the United States Ambassador to India between 1961 and 1963. He was a close confidante of the Kennedys and, in 1962, invited the First Lady of the United States, Jacqueline Kennedy, to tour India and Pakistan. She arrived in mid March along with her sister, Lee Radziwill, and visited Delhi, Agra, Varanasi, Jaipur & Udaipur.

After spending a few days in India, Mrs. Kennedy left for Pakistan. As a farewell gift, Air India presented her with twin six month old tiger cubs named Mohan and Mohini which were born in captivity in the Lucknow Zoo. Unfortunately, both of them died of acute gastroenteritis within a couple of days, reportedly because they were fed the wrong kind of meat.

A few days later, the Pakistani president presented her - a keen equestrienne - with a horse named Sardar which fared much better.

During her trip, Jackie Kennedy acquainted herself with both Jawaharlal Nehru & Indira Gandhi. In an interview conducted in 1964 - after her husband's assassination - she referred to Indira as "a real prune - bitter, kind of pushy, horrible woman".

Indian connection
Connotations

It is possible that the tiger cubs were "replaced" at a later date. An archived article from the New York Times (behind a paywall) appears to indicate so.

While the thought of making a present of tiger cubs is appalling, it is worth noting that there are more tigers in private hands in the USA than in all of India.