TAIPEI (Kyodo) Taiwan on Monday protested comments made by the top Japanese diplomat that its political status was up in the air, threatening to dent relations between the island and its former colonial ruler.

Meanwhile Taiwan's ruling Nationalist Party caucus called for the island's Cabinet to list Japan's chief representative in Taipei as persona non grata over the envoy's remarks on the island's sovereignty.

The caucus made the demand in a formal letter asking for the expulsion of Masaki Saito, who directs Japan's Interchange Association, Tokyo's representative office in Taipei in the absence of official relations. Taiwan President Ma Ying-jeou also condemned the statement, his spokesman said Monday.

"We express regret and solemn opposition to Saito's comment, which is damaging to our government," Taiwan's Foreign Ministry said. "This kind of comment is inaccurate, and our government absolutely cannot accept it."

Taiwan activists protested at the de facto Japanese embassy in Taipei on Monday, three days after Saito told a university forum in Taiwan that the island's status had "not been determined," angering the island government.