Pak says its nuclear arsenal is safe, criticises WikiLeaks

Foreign Office spokesman Abdul Basit described the release of the sensitive documents as "irresponsible behaviour" and said Pakistan is taking stock of revelations concerning the country.

The "irresponsible issuance of sensitive documents regarding foreign and defence affairs is a condemnable act", he said.

The US had warned Pakistan about the release of these documents before they were issued, he said.

US Ambassador Cameron Munter also criticised the release by Wikileaks in an article in a Pakistani newspaper.

"I cannot vouch for the authenticity of any one of these documents...But I can say that the US deeply regrets the disclosure of any information that was intended to be confidential. And we condemn it," he wrote.

The confidential cables show US concern over radioactive material in Pakistan's nuclear power stations and fears that they could be used in terror attacks.

The cables reveal the US has been attempting to remove highly enriched uranium from a research reactor in Pakistan since 2007.

In a May 2009 cable, then US Ambassador Anne Patterson says Pakistan had refused a visit by US experts.

She quoted a Pakistani official as saying that removing the nuclear fuel would be seen in Pakistan "as the United States taking Pakistan's nuclear weapons".

American officials have often expressed concern that extremists could target Pakistan's nuclear programme to steal a weapon or materials needed to build one.

Pakistan has insisted that its nuclear security is good enough to prevent this from happening. Some leaks could also damage Pakistan's relations with other countries.

The king of Saudi Arabia, a close ally of Pakistan, reportedly called President Asif Ali Zardari the greatest obstacle to the country's progress.

"When the head is rotten, it affects the whole body," King Abdullah was quoted as saying.