US Secretary of State Condoleezza Rice pressed Pakistan to cooperate fully in the investigation into the Mumbai attacks but she also warned India against any action that could stoke regional conflict.
In a delicate balancing act aimed at curbing tensions between the two nuclear-armed neighbours, Ms Rice said she had gone to India to show the Bush administration's solidarity and empathy with the Indian people after the attacks on Mumbai that killed nearly 200 people, including six Americans.
"This is the time for everybody to co-operate," Ms Rice told a news conference in New Delhi late today.
But she stressed Pakistan must help India in its investigation into the attacks on the financial hub last week.
"Pakistan has a special responsibility to do so and should do so transparently, fully, urgently and that is the message that we have delivered (to Pakistan)," she said.
India's Foreign Minister Pranab Mukherjee had harsh words for Pakistan, linking groups based there to the attacks in which Indians and foreigners were targeted. US officials have also blamed groups based wholly or partially in Pakistan.
"I informed Dr Rice there is no doubt that the terrorist attacks in Mumbai were perpetrated by individuals who came from Pakistan and whose controllers are in Pakistan," said Mukherjee, with Rice at his side.
Ms Rice said if "non-state actors" were responsible, then it was Pakistan's responsibility to take tough action against them and co-operate in bringing the perpetrators to justice.
Pakistan has promised to act but insists it needs tangible proof, and has also indicated it will not accept an Indian demand to hand over 20 of its most wanted men that New Delhi says are living in Pakistan.
When pressed on whether she would push Pakistan to hand over the 20, Ms Rice skirted around the issue and said she did not want to "get into the specifics".
But she made clear any response by India should not lead to increased tensions between the neighbours, who have fought three wars since independence from Britain in 1947.
"Any response needs to be judged by its effectiveness in prevention and also by not creating other unintended consequences or difficulties," Ms Rice said.
In a two-pronged effort to put pressure on the Pakistanis, the top U.S. military commander flew into Islamabad while
Ms Rice was in India, urging that country to broaden its campaign against militant groups following the attacks in Mumbai.
Admiral Mike Mullen, the chairman of the US Joint Chiefs of Staff, urged Pakistan to "investigate aggressively any and all possible ties to groups in Pakistan" and "take more, and more concerted, action against militant extremists elsewhere in the country".
India's government has come under fire for not heeding attention to warnings about an impending attack.
Ms Rice, who was US national security adviser at the time of the September 11 attacks on the United States in 2001 and came under similar criticism, said it was often difficult to translate information into knowledge to be used to prevent an attack.
"I think perhaps we have some sense of what this is like, the sense of vulnerability, the questions that arise, and the
desire to make every step to try and make sure that it does not happen again," Ms Rice said.
A senior US official travelling with Ms Rice said there was a sense among Ms Rice and others that the Mumbai attacks could provide an impetus for India and Pakistan to work together to fight terrorism, just as happened in the early days after September 11, when nations rallied to support Washington.
Much of that support, however, dissipated when the United States decided in 2003 to invade Iraq.
"There is a feeling that there has to be an opportunity here. The only way we can see a way out of this is to leverage this into a serious effort (to fight terrorism)," said the senior official, who spoke on condition of anonymity.
Meanwhile police in Mumbai said they had found eight kilograms of explosives in a bag left behind last week at the city's train station at the start of a three-day rampage by Islamist militants.
There was no bomb, an official at the train station's police control room said. The station was one of the sites attacked last week by militants.
The 10 Islamist gunmen who killed 183 people in India's financial capital last week were from a Pakistani militant group, investigators said.
India has long said Pakistan is unable or unwilling to act against groups on its soil which launch such strikes and the attacks have threatened to unravel improving ties between the adversaries, who have fought three wars since independence from Britain in 1947.
Islamabad has denied involvement and condemned the Mumbai attacks.
Reuters