Pakistan has denied a report it is in talks to buy between six and eight nuclear reactors from China in a deal worth up to $10bn (£5.8bn).
China has already built a nuclear plant like this in Pakistan
Britain's Financial Times newspaper quoted an official saying construction could begin in 2015 and take 10 years.
Such a deal would add more than 4,000 megawatts of electricity to Pakistan's national grid, the paper said.
But a spokeswoman said that while Pakistan was considering more nuclear energy, the FT report was "baseless".
"As our economy is expanding we require more energy and we remain interested in acquiring safe nuclear energy," Tasneem Aslam of the Pakistani foreign ministry told the BBC.
"But the report about Pakistan's talks with China regarding six to eight nuclear reactors is baseless.
"Since this report has also given specifics of the so-called talks we want to clarify that the report is not true."
Pakistan already has two nuclear reactors, and began building a third with Chinese help at Chashma in Punjab province last week.
At the time Pakistani Prime Minister Shaukat Aziz said Pakistan would import two further 600MW plants from China.
"Co-operation between China and Pakistan in nuclear energy for peaceful use will increase in the future," he added.
Concerns rose over Pakistan's nuclear activities after a top scientist admitted in 2004 to leaking secrets.
Dr AQ Khan shocked the nation and sparked international alarm when he publicly confessed to sharing nuclear technology with North Korea, Libya and Iran.
In September Pakistan urged the US and other Western countries to help it develop civilian nuclear technology to meet its growing energy needs.
Observers say concerns over the illegal trading of nuclear technology from Pakistan - technology which could be used to make weapons - have made it difficult for Islamabad to secure agreement on nuclear collaboration.
Pakistan has sought to allay fears, saying its civilian nuclear plants are run under International Atomic Energy Agency (IAEA) supervision.
The country also has a nuclear-weapon and missile technology programme, and conducted its first nuclear weapons tests in 1998, more than a decade after rival India built its first nuclear weapon.