It would be difficult for Kaohsiung Mayor Frank Hsieh to visit Xiamen under present circumstances, a Xiamen-based scholar said yesterday. Fan Xizhao, director of the Taiwan Research Institute in Xiamen University, said there were many political hurdles to overcome before Mr Hsieh could make his trip to the port city. He said Taiwan authorities had been evasive in responding to the crucial question of whether Xiamen and Kaohsiung were cities of the same country, as stated by Mr Hsieh, who argued that mutual visits by city leaders should be allowed. 'I think this is a step forward and constructive to the development of the cross-strait relations,' Professor Fan said. 'However, officials like [Taiwan Premier] Tang Fei have been evasive in responding to Mr Hsieh's statement. Mr Tang said he supported exchanges between two cities, but he did not say if they are two cities of the same country.' He said that unless Taipei embraced the 'one China' principle, it would be difficult for Mr Hsieh to break the impasse in cross-strait exchanges. There were also other obstacles such as Taiwan's laws restricting cabinet-level officials from visiting the mainland, he said. Professor Fan denied speculation in the Taiwan media that the proposed visit by Mr Hsieh implied the Democratic Progressive Party would play an increasingly important role in cross-strait relations. Mr Hsieh will formally become the DPP chairman later this month. Professor Fan said Mr Hsieh's trip, if it took place, would have little significance in accelerating the negotiation of the proposed stepping-up of direct trade and commercial links across the Taiwan Strait as it hinged on Taipei's attitude on the issue.