JALANDHAR/NEW DELHI, May 14 -- India's new Lakshman Rekha (red line) against terrorism is crystal clear and New Delhi will respond to any future attack fiercely, Prime Minister Narendra Modi said on Tuesday during a surprise visit to the frontline Adampur airbase in Punjab that doubled up as a show of strength.

With the Russian-origin S-400 missile launcher in the background, Modi hailed the achievements of the armed forces in the recent four-day conflict with Pakistan, praised "jointness" in the armed response, and said terror bosses in the neighbouring country were now aware that any attack on India will result in their destruction.

"India's Lakshman Rekha against terrorism is now crystal clear. India will respond strongly if hit by a...