The office of Indian Prime Minister Manmohan Singh issued a statement saying New Delhi remained steadfast in maintaining its historical ties to the Islamic Republic, The Press Trust of India reported.

"It was clarified that our relations with Iran were time-honored and (civilized) in nature and no outside influence or pressure could force India to deviate from this path," the statement read.

The statement added that negotiations regarding the proposed 1,724-mile natural gas pipeline "epitomizes the nature and importance" of the Iranian-Indian relationship.

"India is not under any pressure, nor can it be pressurized to follow a course of action that is not dictated by our enlightened self-interest," it said.