Pakistan offered on Tuesday to work hand-in-hand with India to track down those responsible for the Mumbai attacks but declined to respond immediately to a demand that it hand over 20 terrorist suspects.
Foreign Minister Shah Mehmood Qureshi suggested setting up a "joint investigation mechanism" into the assaults, which left 188 dead.
As tensions mounted between the nuclear-armed neighbours over the siege of India's financial capital, India demanded that Pakistan arrest and extradite the list of terror suspects.
But Qureshi did not respond to the handover request.
Among the suspects was Hafiz Saeed, the founder of the Lashkar-e-Taiba militant group that has been accused of carrying out last week's dramatic assault on Mumbai.
Pakistan's prime minister said his government wanted proof of India's allegation that all the attackers were Pakistanis, while President Asif Ali Zardari denied his country was involved in any way.
"I think these are stateless actors who have been operating throughout the region. The gunmen, whoever they are, they are all stateless actors who are holding hostage the whole world," Zardari told CNN.
"The state of Pakistan is no way responsible," the Pakistani leader added.
CNN and other US networks reported that the United States had warned India in October hotels and business centres in Mumbai would be targeted by attackers coming from the sea.
One US intelligence official had named the Taj Mahal hotel, one of 10 sites hit in the 60-hour siege by gunmen, as a specific target, ABC television said.
It said Indian intelligence officials intercepted a phone call on November 18 to an address in Pakistan used by the head of Lashkar-e-Taiba, revealing a possible attack from the sea.
About 10 gunmen landed in rubber dinghies in Mumbai on Wednesday and wreaked havoc with automatic weapons and hand grenades, in an assault that killed 188 and injured more than 300. The dead included 22 foreign nationals.
India's security and intelligence agencies have come under intense criticism over their handling of the incident.
"Such comprehensive failure was held up to the world's view during 60 hours of unprecedented trauma, featuring 10 heavily armed terrorists who sailed into Mumbai from Pakistan and penetrated Indian defences as if it was child's play," The Hindu newspaper said on Tuesday.
Pakistan outlawed Lashkar-e-Taiba, which has fought Indian rule in divided Kashmir, after it was blamed for the 2001 attack on the Indian parliament -- though Indian officials allege that Pakistan has not enforced the ban.
India and Pakistan have fought three wars since independence and were on the brink of a fourth after the 2001 attack.
But Foreign Minister Pranab Mukherjee stressed that armed conflict was not on the agenda, telling reporters "nobody is talking about military action".
Even so, US Defense Secretary Robert Gates commended India for its restraint after the attacks.
The names on India's list come from suspects originally put together by India after the assault on parliament.
As well as Hafiz Saeed, they include Maulana Masood Azhar, chief of the Jaish-e-Mohammed rebel group, and Dawood Ibrahim, wanted in India on charges of masterminding serial bombings in Mumbai in 1993 that killed around 300 people.
Mukherjee formally demanded "the arrest and hand-over of those persons who are settled in Pakistan and are fugitives of Indian law".
Pakistan has said in the past that it will not hand over any of its citizens to India and denies Dawood Ibrahim, an Indian national, is on its soil.
"They have given us (the names of) some of the organisations ... but that is not evidence," Pakistan Prime Minister Yousuf Raza Gilani told CNN.
The Wall Street Journal reported that Indian police believed a top member of Lashkar-e-Taiba named as Yusuf Muzammil had masterminded the attacks.
Muzammil was identified as the brains behind the attacks by Ajmal Kasab, the only gunman who was captured alive, an unidentified senior police official told the US business daily.
Questions about whether India ignored US intelligence warnings would likely come up in discussions with US Secretary of State Condoleezza Rice, who arrives Wednesday.
She is due to meet Indian officials though there has been no announcement if she will also visit Pakistan, a close ally in the US-led "war on terror" since the September 11 attacks on the United States in 2001.
"In some ways that whole region is like a forest that hasn't had rain in many months and one spark could cause a big, roaring fire. That's what we're trying to avoid," White House spokeswoman Dana Perino said on Monday.