"Pakistan will always spend whatever it takes to build up as many nuclear weapons as possible" due to animosity toward India, said George Perkovich, director of the nuclear policy programme at the Carnegie Endowment for International Peace, a US-based think tank.
US President Barack Obama will travel to India in the first week of November and any signs of engagement with neighbours, especially on nuclear issues, is likely to mar the trip. Moreover, US officials are angered over Pakistan's decision to block the treaty to ban the production of weapons-grade fissile material at the United Nations earlier this year.
But Pakistan is convinced that it should be given a go ahead to build up its nuclear weapons to counter the Indian armed forces since India's civilian-nuclear deal has given it an unfair advantage. However, the Pakistan delegation visiting Washington does not have its hopes high.
A Pakistani official said the delegation will raise the issue of a US civilian nuclear deal next week but that "expectations are very low." The US, the Pakistani official said, "considers India its biggest ally. That's why our demand is rejected."
Full coverage: Indo-US Nuclear Tango
US 'heavy-lifted' nuclear deal, will India repay?
View: Obama kickstarts India's nuclear deal
Nuclear Bill may cost the prime minister dearly
Pakistan gets nuclear deal by proxy