Pakistan will buy four frigates equipped with organic helicopters from China under an agreement signed on Monday, the Pakistan defence ministry said.

Ahead of Chinese Premier Wen Jiabao's visit to Islamabad, the two countries signed the deal for the warships, which will enhance the operational capabilities of the Pakistani navy.

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"The F-22P Frigates will be equipped with organic helicopters specially designed for Anti-Submarine Warfare, Surface-to-Surface and Surface-to-Air missiles along with numerous associated self-defence systems," the Pakistani defence ministry said.

Pakistan President Pervez Musharraf [Images] recently said that the Chinese frigates coupled with F-16s would add an "offensive punch" to the country's armed forces. A number of agreements in the fields of economics, defence and education would be signed during the Chinese Premier's visit, Foreign Office Spokesman Jalil Abbas Jilani said.

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He, however, declined to give details.

Besides visiting Islamabad, the Chinese Premier would be felicitated at a public reception at Lahore [Images] on April 6. "China and Pakistan enjoy close, friendly and all-weather relations," Jilani said.