Taiwan has imposed stricter regulations on Japanese food imports from the regions affected by the 2011 Fukushima nuclear disaster.
The restrictions, which are in line with radiation safety management practices, will be temporary, Reuters reported citing Taiwan president Ma Ying-jeou.
The new rules will allow only those food items to enter which possess Japanese government-issued place of origin certificates.
In addition, certain food products originating from designated places in Japan will have to undergo radiation testing before entering Taiwan.
Tokyo warned Taiwan that it will call for WTO ruling unless the restrictions are eased.
Japan government spokesman Yoshihide Suga said: "Japan's government would like to urge Taiwan to scrap or ease the import restrictions based on scientific perspective."
Since March 2011, Taiwan imposed ban on food products from radiation-exposed Japanese prefectures including Fukushima, Ibaraki, Gunma, Tochigi and Chiba.
Earlier this year, Taiwan received over 200 Japanese food products from Japan's radiation exposed areas near Fukushima Dai-ichi and the products were mislabeled as having originated from other areas.