GENEVA (REUTERS) - Major trading partners of the United States expressed both commercial and systemic concerns about its tariffs plan on Wednesday (March 7) and said they feared tit-for-tat trade actions, a World Trade Organisation (WTO) spokesman said.

China kicked off the debate about the planned tariffs on steel and aluminium at the closed-door meeting.

Delegations taking the floor included the European Union, Canada, Turkey, Russia, Australia, South Korea, Japan, Mexico, India and Brazil.

"We fear that the United States may be opening a Pandora's Box that we would not be able to close," a trade official quoted Canada's ambassador as saying.