Seventeen historical cities across the world issued here Saturday a declaration to establish an alliance for the protection of their cultural heritages.

The mayors and representatives attending the World Expo' s second theme forum supported a proposal by the Suzhou Municipal government to set up an alliance and jointly issued the Declaration for the Establishment of the Historical Cities Alliance -- Suzhou Outlook.

The representatives recognize that the historical cities in all countries and regions each have their own unique cultural heritages, which are precious treasures not only belonging to all countries and nations, but also belonging to the whole of humanity, the declaration states.

With the changes of the history and influences of human activities, too many cultural resources have experienced the corrosion of time or man-made damages and some need the protection of historical cities, the declaration notes.

The alliance advocated more efforts be made to preserve the dignity of cultural heritages, maintain regional characteristics and respect national traditions and promote communication and cooperation among historical cities.

The 17 cities include the Chinese cities of Beijing, Shanghai, Hangzhou, Xi' an, Luoyang, Yangzhou, Suzhou and the Macao Special Administrative Region, and foreign ones including Italy' s Bologna and Venice, Spain' s Barcelona, Mexico' s Mexico City, Kenya' s Nairobi, Egypt' s Cairo, Britain' s Liverpool, Germany' s Konstanz and India' s Pondicherry.

The forum has attracted about 800 participants from nearly 20 countries and regions as well as international organizations to discuss the value of a nation's cultural heritage along with urban regeneration.