In the harshest statement to date, an Indian minister has threatened to break off business, transport and tourist links with Pakistan if it fails to help investigate the Mumbai terrorist attacks.
Home Minister P. Chidambaram told The Times daily: "There are many, many links between India and Pakistan, and if Pakistan does not cooperate and does not help to bring the perpetrators to heel, those ties will become weaker and weaker and one day snap.
"Why would we entertain Pakistani business people? Why would we entertain tourists in India? Why would we send tourists there?"
Chidambaram, however, refused to discuss when such measures might be introduced except to say: "We need cooperation soon."
Asked what Pakistan was doing in connection with the investigation into the Nov 26 attack, Chidambaram told the Press Trust of India: "Zero. What have they provided? Nothing."
The Indian government handed over a dossier to Pakistan on Jan 5 which includes transcripts of phone calls allegedly made during the siege by the attackers and their handlers in Pakistan.
India suspects banned Pakistan-based militant group Lashkar-e-Taiba of training and equipping the assailants. The militant group is also believed to have links to Pakistani intelligence.
India also gave Pakistan a letter from the lone surviving gunman, Mohammed Ajmal Kasab, that reportedly said he and the nine other gunmen were Pakistanis.
Pakistan's Prime Minister has downplayed the significance of the dossier, saying it contained only information and "not evidence", the Associated Press of Pakistan reported.
Addressing Parliament, Yousuf Raza Gilani said: "All that has been received from India is some information. I say information because these are not evidence."
He said the dossier had been handed over to Pakistan's interior ministry for review and reiterated a call for a joint probe into the attacks, calling for "serious sustained and pragmatic cooperation".
"We are prepared to cooperate with India to uncover the full facts," he said.
Pakistan only recently acknowledged that the only surviving Mumbai gunman was a Pakistani, but it insists none of its state agencies played a role in the attacks.
Under international pressure, Pakistan has detained some suspects allegedly linked to the attacks, while repeatedly calling on India to provide evidence to allow prosecutions.
The Mumbai attacks have raised tensions between the two nuclear-armed rivals dramatically. The head of India's army yesterday confirmed that Pakistan has redeployed troops along the two countries' tense border.
General Deepak Kapoor said: "Let me assure you that the Indian army has factored this in its planning."
He did not say whether India had also bolstered its troops along the already heavily militarised border, including the tense Line of Control that divides the disputed Himalayan region of Kashmir.
In another development, one of the witnesses in the Mumbai attack who saw the terrorists land on the city's shores has gone missing.
Police said Anita Uddaiya, who saw the 10 terrorists arrive at the Fisherman's Colony in Cuffe Parade, has disappeared since Jan 11, India Today reported.
The police have launched a manhunt for the missing witness, who had been taken to a hospital earlier to identify the bodies of nine of the terrorists.