The US keeps a close eye on this friendship

Military ruler General Pervez Musharraf had been due to cut the ribbon, but bad weather prevented him from flying to the ceremony.

Instead Pakistan's Minister of Science and Technology Atta-ur Rehman opened the facility in the presence of China's Minister for Science and Technology Liu Jubin.

Friendly relations

China has long given heavy-weight political and military backing to Pakistan, which Beijing sees as a counterweight to India.

The Associated Press news agency reported that Mr Liu delivered a letter from Chinese Premier Zhu Rongji, describing the project as a "symbol of traditional friendly relations".

Musharraf said at a cabinet meeting on Wednesday that China was keen to extend help to Pakistan.

Pakistan's first nuclear power plant was built in the early 1970s in the southern port city of Karachi with Canadian reactors.

Chashma will provide another 600 megawatts of power to the state power authority.

Last year the United States imposed sanctions on Islamabad, which it said had bought nuclear-related equipment from Beijing that could be used for nuclear weapons.

But both countries insist the only nuclear equipment supplied to Pakistan was for the Chasma plant.

Safeguards

Mr Rehman said the nuclear energy produced was meant for peaceful purposes only.

The Pakistan Atomic Energy Commission says the country's two plants both observe international safeguards which prevent irradiated fuel from being used in nuclear weapons development.

The new nuclear power station will provide only a fraction of Pakistan's growing electricity needs.

But supporters of the nuclear programme say it is the answer to increasing electricity demands.

The United States first expressed concern over nuclear cooperation between China and Pakistan in the early 1990s, when Washington said Beijing had sold nuclear-capable M-11 missiles to Islamabad. But both sides denied the charge.