China on Thursday voiced resolute opposition to U.S. unilateral trade protectionism in the shipbuilding sector that ignores World Trade Organization (WTO) rules.

He Yadong, a spokesperson for the Ministry of Commerce, made the remarks after U.S. President Joe Biden pledged on social media to look into a petition from worker unions asking his administration to review China's so-called subsidies for its shipbuilders.

The official said that the accusations made by some U.S. organizations against China are totally untenable, and the main reason for the weakening of the U.S. shipbuilding industry is excessive protection, as various reports have shown.

China's shipbuilding sector thrives on intensive sci-tech innovation by enterprises, which pursue high-end, intelligent and green growth, he stressed, adding that the U.S. side blames China for its own industrial development problems with no factual basis.

"U.S. moves based on Section 301 of the Trade Act of 1974 are unilateral steps, which violate basic WTO principles and blatantly ignore and undermine multilateral rules," He told reporters.

Recalling that previous Section 301 measures taken against China were ruled as a breach of WTO rules, He expressed hope that the U.S. side will make prudent decisions and refrain from repeating its mistakes.

China will pay close attention to the progress of the incident and take all necessary measures to firmly defend its legitimate rights and interests, he added.