BEIJING, March 5 (Xinhua) -- China has never imposed any restrictions on the export of masks and related raw materials, a commerce official said Thursday.

As a major producer of masks, China has been providing protective products to the global market for years. Over 70 percent of the country's annual mask output is for export, Li Xingqian, director of the Department of Foreign Trade of the Ministry of Commerce, told an online press conference.

The ministry has not imposed an export ban on masks or related raw materials since the outbreak of the novel coronavirus epidemic. However, the domestic demand remains high as the country's prevention and control of the outbreak is still at a critical stage, and more companies and factories have returned to business in recent days, he said.

Noting that many countries had offered aid to China in its fight against the epidemic, Li said while overcoming its own difficulties, China is willing to offer medical supplies including masks within in its capacity to other countries to support their fight against the epidemic.

"We are willing to deepen international cooperation and work with other countries to address the common challenge," Li said.