China sent two air force incursions close to Taiwan on Thursday, underscoring its displeasure at the government in Taipei’s bid to join a regional trade deal.

Twenty four People’s Liberation Army aircraft flew into Taiwan’s air defense identification zone, Taiwan’s Defense Ministry said in two separate statements. That was the largest number of Chinese planes to enter the zone in a day since June, when China’s air force sent 28 aircraft close to Taiwan in the biggest sortie this year.

The flights came a day after Taiwan announced it had requested to join the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, an 11-nation group China also applied to join last week. In the past, Beijing has used large-scale incursions to signal its anger at Taiwan for challenging China’s claims to sovereignty over the island democracy.

The dispute wasn’t limited to military maneuvers, with Beijing and Taipei exchanging barbs over the latter’s attempt to join the CPTPP.

“We firmly oppose any official ties between Taiwan and any countries, and firmly oppose Taiwan’s accession into any treaties and organizations that are of official nature,” Beijing’s Foreign Ministry spokesman Zhao Lijian said at a regular briefing Thursday.

The Foreign Ministry in Taipei responded by saying China has no right to comment on the Taiwan government’s application to join CPTPP and that the People’s Republic of China doesn’t represent the people of Taiwan on the international stage.