Pakistan's foreign minister aims to sign a deal on nuclear security during a visit to India beginning Tuesday to underpin peace talks after a deadly attack on a cross-border train, an official said.

Pakistan is hoping for progress in several fields during Khursheed Kasuri's visit, his spokesman Tasnim Aslam said. An agreement on nuclear risk reduction that has been discussed for several months "will hopefully be signed," she said.

"There are a number of agreements that have been in the works for the last five, six months. The texts were finalized. Somehow, the Indians are not able to complete their procedures," she said.

Pakistani and Indian leaders have condemned the bombing of the train, which killed nearly 70 people, as an attempt to derail a three-year-old peace process between the nuclear-armed neighbors. They also have been careful not to apportion blame.

Aslam said it "doesn't make sense" to suspect Islamic extremist groups fighting Indian forces in divided Kashmir, because most of the people on the train were Pakistani Muslims. She declined to say whether Hindu extremists were a more likely candidate.

"We would wait for the Indians to investigate and share their findings with us," she said.

Kasuri was expected to visit a hospital in New Delhi treating Pakistanis seriously injured in the bombing and subsequent fire that tore through two carriages of the train shortly after it left the Indian capital for the Pakistani border late Sunday.

He was to meet his Indian counterpart Pranab Mukherjee and Prime Minister Manmohan Singh on Wednesday.

Aslam said other issues where the peace talks could advance included improving the prison treatment of each other's nationals and relaxing visa restrictions. She gave no details of the nuclear accord.

She said the two sides would also discuss Kashmir, over which Pakistan and India have fought two of their three wars since independence from Britain in 1947.