The mainland's chief cross-Straits negotiator said he would be deeply disappointed if a service trade pact is not approved in Taiwan.

Speaking at a forum on Sunday, Chen Deming, president of the Chinese mainland-based Association for Relations Across the Taiwan Straits, said the trade agreement could boost Taiwan's economy as the economies of the mainland and the island are highly intertwined.

As a follow-up to the 2010 Economic Cooperation Framework Agreement, the trade pact aims to open up 80 of the mainland's service sectors to Taiwan and 64 Taiwan sectors to the mainland.