EU member states agreed to beef up trade rules against cheap imports Tuesday as they wage an ongoing battle over China's stronger trade status at the Word Trade Organization.

After three years of negotiations, the 28 nations voted to give Europe greater leeway to fight cheap imports of raw materials in a move that is sure to deepen a growing trade feud with China.

"This is a major breakthrough," said Peter Ziga, the trade minister from Slovakia, which holds the European Union's six-month rotating presidency.

"Europe cannot be naive and has to defend its interests, especially in case of dumping," he added.

The changes came despite the opposition of Britain and Sweden, which claimed that the measures would hurt the auto sector and open a dangerous road towards protectionism.

Those fears have grown since the election of President-elect Donald Trump on a mandate to curb open international trade in the United States, the world's biggest economy.

Steelmakers were especially keen for the changes after being battered by a collapse in prices due to China-led oversupply and a wave of cheap imports.

The measures agreed on Monday change the so-called "lesser duty rule", which strictly limits EU anti-dumping tariffs.

Under the existing system, the US can impose far harsher tariffs than the EU on Chinese steel imports.

As an example: For cold rolled steel, the EU's duties stand at 21 percent, while the US imposes an average 265 percent duty.

"We are finally putting an end to this self-censorship," a European diplomat told AFP.

The breakthrough at the EU came a day after China began a legal challenge at the World Trade Organization over the reluctance by Brussels and Washington to treat Beijing as a "market economy".

When China joined the WTO in 2001 it was written into the terms of the deal that member states could treat it as a non-market economy for only 15 years.

The deadline passed on Sunday, but the US, EU and Japan have so far opted to ignore the change and preserve the tougher rules that protect them from illegally cheap Chinese products.

"We regret that China is launching this dispute now despite the fact that the Commission has already made a proposal to amend the legislation in question," said Daniel Rosario, a spokesman from the commission, which handles trade policy for the EU.