HARBIN -- A senior official on Saturday called on the mainland and Taiwan to "actively" discuss their political relations under special circumstances that the country has not achieved complete unification.

Top political advisor Jia Qinglin said authorities on both sides should fully use their political wisdom, take more substantial action to consolidate their common ground, and show tolerance for each other's differences in order to pave the way for gradually resolving underlying issues concerning mainland-Taiwan relations.

Jia, chairman of the National Committee of the Chinese People's Political Consultative Conference, made the remarks at the opening ceremony for the 8th Cross-Straits Economic, Trade and Culture Forum that kicked off in Harbin, capital of northeast China's Heilongjiang province.

Jia said the cross-Strait relationship should develop on the basis of political mutual trust, which requires the two sides to seek common ground while shelving differences.

Increasing cross-Strait political mutual trust currently means maintaining the "one China" framework, Jia said, stressing that China's territory and sovereignty is not divided although the mainland and Taiwan have not been unified.

Both sides should abandon all types of untimely oppositional attitudes and promote the concept that both sides belong to one family, he said.

The core meaning of the "one China" framework is that the mainland and Taiwan belong to one country, and cross-Strait relations are not state-to-state relations, he added.

Jia, also a member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, said the past four years marked a milestone in the progress of the cross-Strait relationship, as the cross-Strait situation was the most peaceful during this period.

At the beginning of this year, when facing an important choice concerning the future development of cross-Strait relations, Taiwanese compatriots explicitly expressed their desires to maintain a stable cross-Strait relationship, continue negotiations and expand exchanges, Jia said.

The Taiwanese compatriots' choice to support the peaceful development of the cross-Strait relationship proves that peaceful development is an appropriate track that should be followed, he said.

A visiting Taiwan delegation headed by Wu Poh-Hsiung, honorary chairman of the Kuomintang (KMT) Party, attended the opening ceremony of the forum.

Also at the opening ceremony, KMT Vice Chairman Feng-cheng Lin relayed a congratulatory speech by KMT Honorary Chairman Lien Chan, who expressed hope that attendees to the forum could contribute their wisdom in promoting cross-Strait economic cooperation and cultural exchanges.

The forum was established in April 2005 in accordance with a common vision of the cross-Strait peaceful development achieved by the leaders of the CPC and Kuomintang.

So far more than 120 proposals and suggestions initiated at the forum have been accepted by authorities of the mainland and Taiwan.

The Kuomintang's Chairman Ma Ying-jeou said when seeing off the Taiwanese delegation Thursday in Taipei that the forum should be expanded and promoted.

Wu Poh-Hsiung said at the forum that although the forum was established by the KMT and CPC, it has opened its door wider to not only participants from the CPC and KMT but also other political parties in the island.

Among more than 200 members of the Taiwanese delegation to the forum, the KMT members account for less than one third.

Wu said he was willing to see dialog between the mainland and some party in Taiwan if the party was ready to "change its course from a dark one to a bright one."

Jia urged the mainland and Taiwan to promote reciprocal economic cooperation and together improve their global competitiveness.

Both sides should accelerate the follow-up negotiations for the Economic Cooperation Framework Agreement and promote the cross-Strait financial cooperation, Jia added.

Companies from the mainland and Taiwan should work together to build indigenous brands of the Chinese nation and exploit the world market, he said.