The pledge by Foreign Secretary Shyam Saran follows a December 2003 crackdown by the Bhutanese military on insurgent groups from India's northeast sheltering in the Buddhist nation.

Speaking to a seminar in New Delhi, Saran said the joint operation had been a "milestone" in the fight against terrorism, the Press Trust of India reported.

"We look forward to continue this cooperation by jointly upgrading our border infrastructure and management, including through better roads and communication links as well as information-sharing," he said.