Taiwan said Tuesday it would protest to Beijing and Belgium after its delegation was barred at a global industry conference in Brussels due to complaints from China.
It is the latest bout of diplomatic sparring between Taiwan and China as tensions simmer ahead of the inauguration of Taiwan's president-elect, Tsai Ing-wen, in May.
Beijing does not trust Tsai's historically pro-independence party and ties are predicted to deteriorate.
Although it is self-ruling, Beijing considers Taiwan a province awaiting reunification since the two sides split after a civil war on the mainland in 1949.
Taiwanese officials attending the Organisation for Economic Cooperation and Development (OECD) steel symposium in Brussels were barred from a meeting Monday after China complained to Belgium they were not sufficiently high-ranking, Taiwan's economic ministry said.
Taiwan is not an OECD member but has attended the organisation's steel committee meetings since 2005.
"Our delegation protested on the spot, and pointed out that nearly half of the heads of delegations held similar ranks as us," Taiwan's Ministry of Economic Affairs said in a statement.
The Taiwanese group were unable to enter the meeting because of China's complaint, it added.
"That is an unreasonable and discriminatory act," the statement said.
Taiwan's representative to the European Union has asked the island's Mainland Affairs Council to lodge a complaint with China, and the delegation will submit a protest letter to the Belgian government Tuesday, it said.
Taiwan's five-member delegation included a section chief from the economic ministry, as well as representatives from the trade bureau and the island's steel sector.
Taiwan is barred from a number of international organisations as Beijing's global dominance has grown and its number of allies is dwindling -- the island now only has diplomatic ties with 22 states.
The Brussels snub comes after Taiwan last week blasted Beijing for being "rude and violent" over the deportation of 45 of its citizens from Kenya to China where they face investigation for fraud.
Taiwan said it will send 10 officials to the mainland Wednesday in an attempt to bring the suspects back to the island for investigation and trial.
The island has also alleged that Beijing sought to deport another group of Taiwanese implicated in telecom fraud in Malaysia.