China's top security official paid a surprise visit to Afghanistan, where he met with President Hamid Karzai on issues ranging from investment and bilateral trade to to terrorism and drug trafficking, China's state-run news agency said.

The visit Saturday by Zhou Yongkang, a member of Communist Party's politburo, the elite group of 25 men who run China, was the first visit by a top Chinese official since 1955, Xinhua reported.

Beijing kept the visit secret because of security concerns, the agency said.

"It is the consistent policy of the Chinese government and the (party) to consolidate and develop China-Afghanistan relations," Zhou said in a statement reported by Xinhua.

Zhou also said China is willing to make "due contributions" to peace and stability.

"We will continue to provide assistance to Afghanistan with no attached conditions and sincerely hope the Afghan people can regain peace as soon as possible and build a better home in a peaceful environment," he added.

Karzai and Chinese President Hu Jintao held a summit in Beijing in June. The two countries decided at the time to develop a strategic and cooperative partnership, Xinhua reported.