New York: Former US President Bill Clinton has said he was "deeply concerned" about India's underground nuclear tests in 1998 as it had shaken efforts to ban nuclear testing and that he was unable to persuade then Prime Minister Atal Bihari Vajpayee to agree to the Nuclear Test Ban Treaty.

Writing in his 957-page memoirs 'My Life', Clinton says he was "deeply concerned" about India's five underground nuclear tests as they had shaken the efforts to ban nuclear testing. After Indian tests, "I urged Pakistan's (then) Prime Minister Nawaz Sharif not to follow suit, but he could not resist the political pressure," Clinton writes, adding public opinion in both nations strongly supported the tests but it was a "dangerous proposition".

However, Vajpayee did join him in pledging to forgo future tests, and "we agreed upon a set of positive principles that would govern our bilateral relationship that had been cool so long," Clinton writes.

The former President, who visited India and Pakistan in March 2000, says he was deeply concerned about New Delhi's nuclear explosions not only because he considered it "so dangerous" but also it "set back my policy of improving Indo-US relations and made it harder for me to secure senate ratification of the Comprehensive Test Ban Treaty."

During his visit to India, Clinton says he was unable to persuade Vajpayee, with whom "he got along well," to agree to the Nuclear Test Ban Treaty. "But I already knew that as Strobe Talbott (Deputy Secretary of State) had been working with Foreign Minister Jaswant Singh and others for months on non-proliferation issues."