BEIJING, April 7 (Xinhua) -- China will provide more convenience for domestic firms to apply for the exemption of additional tariffs imposed on some U.S. products by optimizing an online declaration system, the Customs Tariff Commission of China's State Council said Tuesday.

The system, once upgraded, would allow enterprises to submit their procurement plans more conveniently and facilitate the processing of exemption applications, especially for those involving a procurement amount of less than 3,000 U.S. dollars or when the time of import approached, according to a statement of the commission.

The system would soon open its modification functions to accelerate re-editing for approved procurement plans, transaction records and other information.

China's tax authority started to accept applications of domestic firms for the exemption of additional tariffs imposed on some U.S. products within a certain period of time on March 2, as part of the support for enterprises' imports from the United States based on business considerations.