Anne Krueger: Steel firms should blame themselves

The move violated World Trade Organisation (WTO) commerce rules, she suggested.

"For one thing, it is not totally in accord with international trading rules that the US has signed up to," said Ms Krueger, a prominent conservative economist, who joined the IMF from Stanford University.

The comments came hours after the European Union unveiled details of plans to slap tariffs on 378m euros ($341m; �236m) worth of imports from the US, in retaliation for the steel duties.

Storing up trouble

WTO rules allow governments to impose temporary import curbs if a domestic industry is proved to be being damaged.

But while the US introduced the tariffs to protect the country's ailing steel industry, the sector's plight was its own fault, Ms Krueger said.

US steel mills had yet to implement the cost cutting measures needed to compete on the world stage.

"Protection will at best delay a necessary restructuring," she said.

Tariff targets

Earlier on Tuesday, the EU, which has lodged an official complaint with the WTO over the tariffs, unveiled a list of products ranging from frozen vegetables to paper products proposed for import duties.

US cigarettes would be subject to 30% duties, and some fruit juices to a 100% levy, said the EU, which had until 17 May to present its proposals to the WTO.

Harley Davidson motorcycles and bed linen were among goods dropped from the list following deliberation among EU officials.

EU governments are to say next month whether retaliatory measures will be imposed.