The European Union on Thursday launched a case at the World Trade Organization (WTO) against China for targeting Lithuania over its stance on Taiwan.
"Launching a WTO case is not a step we take lightly," said EU trade chief Valdis Dombrovskis in a statement.
"However, after repeated failed attempts to resolve the issue bilaterally, we see no other way forward than to request WTO dispute settlement consultations with China," he added.
Lithuania, one of the smallest countries in the European Union, made waves in July when it allowed Taiwan to open a diplomatic outpost in Vilnius.
The move outraged Beijing, which does not recognize Taiwan as a state and considers the island a rebellious territory of the mainland.
By going to the WTO, the EU lent support to accusations by Lithuanian business leaders and officials that the row has resulted in China blocking imports from Lithuania and other economic restrictions.
Dombrovskis said that the bloc would continue to pursue diplomatic solutions to the feud, and has raised the problem with his Chinese counterparts in recent weeks.
The United States has signaled its support for the European Union and Lithuania in the row.