WASHINGTON, June 23: The White House on Wednesday refused to get involved in a discussion over nuclear scientist Dr A.Q. Khan’s failing health and Pakistan’s continued refusal to allow foreign nationals to interrogate him, confining itself to highlighting Washington’s success in dismantling the network allegedly led by him.

“The breaking up of the A.Q. Khan network was a great success,” White House Press Secretary Scott McClellan told a briefing. “There are a number of countries that have been involved in helping us to dismantle the Khan network, and we continue to move forward, working with other countries, to stop the spread of weapons of mass destruction.”

Mr McClellan was responding to a journalist who had suggested that because of Dr Khan’s failing health the US and other nations should renew their efforts to seek access to the scientist to know more about the network.

“Combating proliferation has been a top priority for this administration,” the spokesman said.