Pakistan and India on Monday exchanged lists of their nuclear sites under an agreement to swap such information annually on New Year's Day to prevent attacks against each other's nuclear facilities, the foreign ministry said.
The agreement signed in 1988 between the South Asian arch rivals came into force in 1991 and the first such exchange of information was on January 1, 1992.
Under the agreement both Pakistan and India are to refrain from attacking each other's nuclear facilities in the event of a war.
"Lists of nuclear sites were exchanged between Pakistan and India on Monday," foreign ministry spokeswoman Tasnim Aslam said.
India conducted nuclear weapons tests in May 1998 and Pakistan, in a tit-for-tat response, detonated its own devices a few days later.
The rivals have fought three wars, two of them over the Himalayan region of Kashmir which is divided between them and claimed in full by both.
After coming close to another war in 2002, in January 2004 they began talks to resolve all their disputes including Kashmir.
In October 2005 the two countries formalised an agreement on pre-notification of ballistic missile tests. They have also set up a telephone hotline to prevent accidental nuclear conflict.
The India-Pakistan peace process was put back on track after foreign secretary-level talks in New Delhi in mid-November, during which the two sides agreed to set up a new anti-terror panel.
India had put on hold the nearly three-year-old talks in the face of public outrage over July's deadly attacks on Mumbai's commuter network, which New Delhi blamed on Pakistan's spy agency and a Pakistan-based militant group.
Islamabad denied any involvement in the blasts, which killed 186 people.
New Delhi accuses Islamabad of arming and training Islamic militants battling its rule in Muslim-majority Indian Kashmir and sponsoring attacks elsewhere in the country.