Pakistan is watching anxiously for India's reaction to China's latest nuclear weapon test.
Islamabad also wants to see how New Delhi will react to China's announcement of a test moratorium after it has exploded another device in September.
Pakistan is under pressure to ratify the Comprehensive Test Ban Treaty in Geneva before June 30. The Western nuclear powers see Pakistan, India, China and Israel as the major obstacles to a worldwide ban.
The Pakistan Government's position is largely dependent on India's next move. Islamabad has usually refused to comply with demands to open up its nuclear facilities to inspectors unless India did the same.
Prime Minister Benazir Bhutto said signing the treaty unilaterally would 'send the wrong signals' and bring pressure on Pakistan to take other steps on its own.
'Many people in Pakistan are already confused that, when India has talked about testing a second nuclear device and when the Indian Prime Minister has come out and said that he will not close the nuclear option, there has not been more of an international outcry,' she said.