Hillary Clinton, U.S. secretary of state, speaks during a news conference at Hyderabad House in New Delhi, India, on July 19, 2011. (Graham Crouch/BLOOMBERG)

Secretary of State Hillary Rodham Clinton called on Pakistan to prosecute “fully and urgently” those who carried out the 2008 attacks in Mumbai and said Washington would not tolerate any countries giving “safe havens and free pass” to terrorists.

Pakistan’s lag in prosecuting Islamists suspected of carrying out the three-day siege in 2008 has been a main irritant in the fractious relationship between India and Pakistan, two key U.S. allies.

While Clinton said the United States was pushing Pakistan in that direction, she also took pains to emphasize Pakistan’s role as an important ally.

“There is a limit to what both the U.S. and India can do, but we intend to press as hard as possible,” she said.

Clinton also said that she was optimistic about the India-Pakistan relationship, with both sides agreeing to resume talks after a long and frosty silence since 2008. The foreign ministers of both countries are expected to meet in New Delhi next week.

“We are encouraged by the dialogue occurring between India and Pakistan,” Clinton said.

Clinton spoke to reporters after a meeting with Foreign Minister S.M. Krishna and other top Indian officials to discuss U.S.-India collaboration on security, counterterrorism, education, trade and science.

Discussion of terrorism dominated much of the day, however, with the deadly bombings last week in Mumbai looming over the day’s meetings. Clinton said the U.S. government also felt “deep sympathy and outrage” at the coordinated bombings.

Krishna expressed concerns that the drawdown of U.S. troops in neighboring Afghanistan could allow a resurgence of Taliban in the region.

“We have impressed on the United States and other countries who have a major presence in Afghanistan that it is necessary for them to continue in Afghanistan,” Krishna said.

The two sides also discussed a controversial civil nuclear energy pact that would allow U.S. companies to begin selling billions in nuclear technology to India but that has run into legal problems.

The main sticking point are Indian laws dictating who would be liable in nuclear accidents, with U.S. companies unwilling to sell if they are held responsible.

“We need to resolve those issues that still remain so we can reap the rewards of the extraordinary work both our governments have done,” Clinton said.

Clinton also met with Indian Prime Minister Manmohan Singh, Congress party chief Sonia Gandhi and opposition leader Sushma Swaraj.

On Wednesday, Clinton is scheduled to give a policy speech in the southern city of Chennai, where U.S. companies such as Ford and Caterpillar have made significant investments. The two countries also signed an agreement to work closer together on cybersecurity.