After speaking with the country's leaders, Rice said that the government is committed to the war on terror and will follow any leads to bring the terrorists to justice.
"Pakistan should also take the necessary steps to prevent any non-state actors from indulging in such activities against any country from its soil," Rice said, according to the New York Times.
The attacks, carried out over three days in India's financial capital, claimed the lives of at least 171 people, including six Americans.
Rice's visit, aimed at easing tensions between the two nuclear-armed countries, came as more evidence surfaced linking the attackers to Pakistani military group Lashkar-e-Taiba. On Thursday, Mumbai police identified a second attacker with links to the organization, which has roots fighting Indian rule in the disputed Kashmir region.
The only surviving attacker, identified as 21-year-old Mohammed Ajmal Kasabj, told interrogators that a Lashkar-e-Taiba commander named Zaki-ur-Rehman Lakhvi helped engineer the attacks, according to Indian police.
Pakistan has denied any government involvement in the attacks and pledged to help track down the terrorists.
"The government will not only assist in investigations but also take strong action against any Pakistani elements found involved in the attack," President Asif Ali Zardari said.
Zadari and Prime Minister Yousaf Raza Gilani, are leading the transition of Pakistan's civilian government that came into power only eight months after being ruled by former army chief Pervez Musharraf.
On Wednesday, Rice met with Indian officials in their capital.
"This is the time for everybody to cooperate," Rice said in India during a news conference with Indian Foreign Minster Pranab Mukherjee.
When it came his turn to speak, Mukherjee took a stronger line.
"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," he said.
The NewsHour's Simon Marks was in India during Rice's visit and reported Indian officials are interpreting her speech as sending a strong message to Pakistan.
"The Indians told me tonight that they were extremely pleased with what they heard from the secretary of state during her visit to Delhi, namely that she wants Pakistan to play a more responsible role," he said.
U.S. Admiral Mike Mullen was also in the region for meetings with Indian and Pakistani officials.
