New Delhi | Nuclear sabre-rattling is Pakistan's "stock-in-trade", New Delhi said on Monday, in a strong response to Pakistan Army Chief Field Marshal Asim Munir's nuclear threat directed at India from the US soil.

India said Munir's remarks reinforced the well-held doubts about the integrity of nuclear command and control in Pakistan where the military is "hand-in-glove" with terrorist groups.

In a statement, the Ministry of External Affairs (MEA) said India has already made it clear that it will not give in to nuclear blackmail and that it will continue to take all steps necessary to safeguard national security.

It is also regrettable that these remarks should have been made from the soil of a friendly third country, the MEA said in an apparent message to the US.

In an address to Pakistani diaspora in Florida's Tampa, Munir reportedly made the nuclear threat in case his country faced an existential threat in a future war with India.

The Pakistani Army Chief also warned that Islamabad would destroy Indian infrastructure, if they hit water flow to Pakistan.

"We are a nuclear nation. If we think we are going down, we'll take half the world down with us," media reports quoted him as saying.

The Pakistan Army Chief's comments are part of a pattern in Pakistan as whenever the US supports the Pakistan military, they always show their true colours of aggression, government sources said.

It is a symptom that democracy does not exist in Pakistan and it is their military which controls the country, they said.

"Emboldened by reception and welcome by the US, the next step could possibly be a silent or open coup in Pakistan so that the Field Marshal becomes the President," said a source.

Munir is currently on a visit to the US, his second in two months.