A container ship docks at the Port of Ningbo, East China's Zhejiang province.[Photo/Xinhua]

BEIJING - China's anti-dumping probes against US products were legal procedures, a spokesperson with the Ministry of Commerce (MOC) said Thursday.

In response to a question whether China's probes were counter-measures to a US investigation into China's intellectual property practices, MOC spokesperson Gao Feng told a press briefing that both probes were legal.

The anti-dumping probe into optical fiber preform products imported from Japan and the United States, starting from Aug 18 this year, was in response to legitimate review applications filed by domestic industry representatives, Gao said.

China launched anti-dumping measures to optical fiber preform imports from Japan and the United States from Aug 19, 2015, with an implementation period of two years.

As for the anti-dumping probe into dispersion unshifted single-mode optical fiber products imported from the United States and the European Union, which began from Aug 22 this year, all procedures are according to law, Gao said.

Gao reiterated that China would take all appropriate measures to defend its legal interests in response to the US trade investigation as it damaged the international trade system and cast a shadow over China-US economic and trade ties.

US Trade Representative Robert Lighthizer last week formally initiated an investigation into China's intellectual property practices under a rarely used trade law, despite worries about potential harm to China-US trade ties.

Section 301, which was heavily used in the 1980s and early 1990s, allows the United States to unilaterally impose tariffs or other trade restrictions on foreign countries. But the country has rarely used the outdated trade tool since the World Trade Organization was established in 1995.