Pakistan today said that nuclear proliferation network of atomic scientist A Q Khan was a "closed chapter" and the country is "mindful of its responsibilities as a nuclear weapon state as well as its international obligations."

"A Q Khan is a closed chapter," Prime Minister Yousuf Raza Gilani [Images] said in his response to the US State Department's sanctions on Khan, his 13 associates and three companies for their involvement in nuclear proliferation.

"The sanctions are not against the state or government. The US has, in fact, applauded Pakistan's contribution to promote global non-proliferation," Gilani said in an official statement.

Pakistan is "mindful of its responsibilities as a nuclear weapon state as well as its international obligations", he said.

Three of the 13 individuals named by the US State Department as being involved in the nuclear proliferation network are Pakistani nationals. The rest of the people implicated in Khan's proliferation network are of other nationalities.

Khan has been under house arrest since early 2004, when he confessed to involvement in proliferating nuclear technology and know-how to countries like Libya and North Korea.

However, Khan retracted his confession last year and approached a Pakistani court to direct the government to lift restrictions imposed on him.