During a joint news conference with Rice, Foreign Minister Pranab Mukherjee said, "there is no doubt the terrorist attacks in Mumbai were perpetrated by individuals who came from Pakistan and whose controllers are in Pakistan."
Rice came here as part of a U.S. effort to ease tensions in the region after a three-day terrorist attack killed 171 people in India's financial capital. She said the United States expects all "responsible governments" to help with the investigation and "Pakistan has a special responsibility to do so and to do so transparently, urgently and fully."
"The responsibility of the Pakistani government should be one of cooperation and of action," she said.
During the new conference, Mukherjee vowed to bring the militant leaders to justice.
"The government of India is determined to act decisively to protect Indian territorial integrity and the right of our citizens to a peaceful life with al the means at our disposal," he said.
Rice assured Mukherjee: "We are going to work very closely with you in any way you can to try to get to the bottom of what happened and then help you act on that."
She was asked at one point if the United States believes the al-Qaida was involved.
"Let me be very clear: We are not saying al-Qaida is the perpetrator here," she replied. " ... There are elements of this - the sophistication of it - that remind us that these extremenists ... that they are perhaps learning from each other, they move in the same circles. But clearly the sophistication of the attack was what I was addressing.
Speaking to reporters earlier, Rice suggested that the United States is especially alarmed by the careful targeting and efficiency displayed in the Mumbai attacks and said "this is a different situation."
Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, was in Pakistan on Wednesday.
In Washington a Mullen spokesman said the attacks reflect a growing sophistication among extremist groups. The United States is encouraging a regional approach to security concerns.
Defense Secretary Robert Gates said Tuesday that U.S. and British citizens were the targets of the violent siege in Mumbai last week, although most of those killed in India's financial capital were from India.
Six Americans died.
The same group that carried out last week's attack is believed to be behind the 2006 Mumbai train bombings that killed more than 200, National Intelligence Director Mike McConnell said Tuesday during a speech at Harvard University.
McConnell did not identify the group by name. However, the Indian government has attributed the 2006 attack to Lashkar-e-Taiba, a Pakistani terrorist group based in Kashmir, and the Students Islamic Movement of India.
McConnell is the first U.S. official to publicly identify Lashkar as the likely perpetrator. Earlier Tuesday, a senior State Department official told reporters only that evidence suggests that the brutal, prolonged attack had some roots in Pakistan. Privately, U.S. and foreign counterterrorism officials fingered Lashkar last week.
Rice delivered U.S. condolences in the Indian capital, but her message at the start of an emergency tour was directed largely at Pakistan.
The United States is trying to ease tensions in the region after a three-day terrorist attack killed 171 people in India's financial capital.
Indian and U.S. officials have pointed the finger at Pakistani-based groups in the attacks. Rice said the operation is similar to the type of terrorism carried out by al-Qaida but she said she would not leap to any conclusions about who is to blame.
