HANOI, Nov. 26 (Xinhua) -- The investigation launched by the United States' Department of Commerce over the dumping of welded steel pipes from five countries, including Vietnam, is groundless, said a Vietnamese official on Thursday.

Le Hai Binh, spokesperson of Vietnam's Ministry of Foreign Affairs, told a regular press briefing here that Vietnamese companies are operating in accordance with the market mechanism without subsidies from the Vietnamese government and do not dump their products in the U.S. market.

The U.S. side should handle the issue in an objective manner in line with trade liberalization and in accordance with commitments to multi-lateral trade liberalization as well as the growing trade ties between Vietnam and the U.S., Binh said.

In late October, several U.S. steel pipe producers proposed U.S. trade regulators to impose anti-dumping duties on certain welded steel pipes from five countries, including Vietnam.