TAIPEI, Taiwan - Taiwan has warned China its demand that a Taiwanese delegation to the Tokyo International Film Festival be renamed could damage fast warming ties, media said Monday.

The Taiwanese warning came as China left the film festival after failing in a push for renaming the Taiwanese delegation in a way that would suggest that the island was part of China.

"Any unfriendly move could easily harm hard-won goodwill and mutual trust," Lo Chih-chiang, the spokesman of Taiwanese President Ma Ying-jeou, told the state-affiliated Central News Agency.

"It has also hurt the feelings of the Taiwan people... the mainland authorities must not consider this issue lightly, but should immediately act to make amends over it."

The severe warning came after Jiang Ping, the head of the Chinese contingent at the festival, said before the opening of the ceremony Saturday that the Taiwan delegation should be renamed the "China Taiwan" or "Chinese Taipei."

He blamed the festival authorities for the flap.

His Taiwanese counterpart flatly rejected the call, and in the wake of the row, stars from both delegations missed the walk along the "green carpet" -- changed from the traditional red to highlight environmental concerns -- which kicked off the festival.

Taiwan's Premier Wu Den-yih also rebuked Jiang, saying the demand was "unreasonable and rude" and Jiang had made a "serious mistake".
Jiang has decided to pull out of the film festival after his demand was rejected by the festival organisers.

The dispute comes amid a simmering row between China and Japan over a contested island chain in the East China Sea, sparked more than six weeks ago when Tokyo arrested a Chinese fishing boat captain near the rocky islets.

China and Taiwan split at the end of a civil war in 1949. Beijing still considers the self-ruled island part of its territory awaiting reunification.

"It is regretful that the Chinese delegation has decided to pull out of festival-related event because the organisers covertly violated the One-China Policy," the Global Times quoted Jiang as saying.

"It has nothing to do with our Taiwan compatriots. It is the fault of the Tokyo organisers," said Jiang, who is also a senior official in the film division of China's State Administration of Radio, Film and Television (SARFT).

Nine Chinese-language films that were to have been screened in a China-specific part of the festival have been pulled, the Global Times reported.

One of two Chinese films in competition, "The Piano in a Factory", has also been withdrawn, but the other, "Buddha Mountain", will be screened, the newspaper quoted a public relations officer linked to that movie as saying.

In Taipei, government spokesman Johnny Chiang said the delegation from Beijing "should not use politics to interfere in movie exchanges".

The name issue has long been a sensitive topic for the island and its giant neighbour, which split in 1949 at the end of a civil war.

Ties between Taipei and Beijing have improved markedly since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 on a platform of ramping up trade links and allowing in more Chinese tourists.

But Beijing still regards the island as part of its territory awaiting reunification, by force if necessary.