"Pakistan and China have signed agreement for Chashma-3 and Chashma-4 ... 680 megawatts of electricity will be generated from these two new plants," Qureshi said.
He did not say when they would be built or what assistance China would provide.
Pakistan is suffering from acute power shortages with officials saying that there is a shortfall of up to 4,000MW.
The deal with China comes after the US refused to offer Pakistan a nuclear deal similar to one given to neighbouring nuclear power India.
Richard Boucher, US assistant secretary of state for South and Central Asian affairs, arrived in Islamabad on Saturday for a series of meetings.
He met Rehman Malik, the head of the interior ministry, and was expected to hold talks with Zardari and Yousuf Raza Gilani, the Pakistani prime minister, with security issues high on the agenda.
Chinese leaders "do recognise Pakistan's need, and China is one country that at international forums has clearly spoken against the discriminatory nature of that understanding" between Washington and New Delhi, Qureshi said.
But Washington has pointed to Islamabad's poor record on nuclear proliferation and the role played by Abdul Qadeer Khan, a Pakistani scientist, in passing nuclear knowledge to Iran, Libya and North Korea.
The US deal with India allows American businesses to sell nuclear fuel, technology and reactors to India in exchange for safeguards and UN inspections of India's civilian, but not military, nuclear installations.
'Friends of Pakistan'
Qureshi also said China would participate in a "Friends of Pakistan" conference, aimed at helping the country secure funds to overcome a balance of payments crisis, due to take place in Abu Dhabi next month.
According to uncorroborated media reports, Zardari requested more than $3bn support during his visit to Beijing.
Shaukat Tarin, the recently appointed adviser to the prime minister on economic affairs, said Chinese companies had committed to invest $1bn in Pakistan by June next year.
Pakistan plans to set up industrial zones for Chinese firms, Chinese banks intend opening branches in Pakistan, and Chinese executives from the information technology and telecommunications sectors are due to seek opportunities for investment.