NEW YORK, Feb 6: The US State Department has again welcomed efforts by the Pakistan government to investigate and punish those involved in nuclear proliferation.

State Department spokesman Richard Boucher said at his briefing on Thursday that the US appreciated the steps taken by Pakistan "to prevent operations of a private network that would be involved in proliferation".

Asked whether sanctions could be invoked against Pakistan if it was proved that US laws were violated, Mr Boucher said: "As far as the question of sanctions, there's a multitude of US laws that are involved when there are transfers, whether they're - sometimes it depends on whether they're government entities, individuals. You can get hit or listed in different ways. It depends on the facts of this particular case - of the particular matter."

Describing the parameters of government's responsibility on the issue, Mr Boucher emphasized that "the responsibility of governments is to ensure respect for international standards and laws...and to make that effort as effective as possible."

Mr Boucher added that it was important that measures to check proliferation should be "comprehensive and they be enduring. We'd also expect that Pakistan will share information that they're unearthing in their ongoing investigation with the international community."

"As far as the specifics of what happens to Dr Khan", the spokesman said, "other than making sure that he and whatever other individuals or networks in Pakistan might have been involved in this trade don't transfer anything again, as far as the specifics of sentencing or pardons or whatever, that really is a matter for Pakistan to decide, and they'll take, I'm sure, appropriate measures under Pakistani law and regulations to ensure that he's - he and his associates are no longer able to endanger the international community."

He reiterated that "the spread of nuclear weapons and technology is a matter of global concern" noting "that the United States has urged all nations that have this technology to take precautions to ensure that it is properly controlled, that it does not fall in the hands of rogue states, non-state actors and individuals".

Asked as to what the US considers appropriate action against those found guilty of proliferation, Mr Boucher said: "I don't think it's a matter for the United States to sit in judgement on.

I think it's a matter that we think what's important in this case is really two things: one is that the network and the individuals who were doing this in Pakistan or from Pakistan be found out, stopped, prevented from making any such transfers again; and second of all, that the information that they develop in their information is shared with the international community, because the international community as a whole needs to go after this network that extends far beyond Pakistan in some cases."

WHITE HOUSE: The White House on Thursday applauded President Pervez Musharraf for breaking up one of the world's largest nuclear proliferation networks.

Answering questions aboard Air Force One as President George Bush travelled to South Carolina, White House spokesman Scott McClellan noted that the actions of Pakistan had broken up the proliferation network.