New Zealand will not be making any threats of retaliation against Donald Trump's plan to put tariffs on imports of steel and aluminum, Trade Minister David Parker says.

Photo: RNZ / Richard Tindiller

Mr Trump is coming under intense pressure from US business interests, foreign trading partners and international trade organisations to pull back from his tariff plan.

He has got some bipartisan support from lawmakers, mainly from America's rust-belt states, who believe the move will help revive the steel industry.

Condemnation of the moves has otherwise been widespread.

However, New Zealand would not be adding its voice to the criticism, with Trade Minister David Parker saying New Zealand will not be making any threats of retaliation.

"We wouldn't be responding by the threat of trade retaliation ourselves, which I see has been the response of some countries," he said.

"But we would certainly be advocating on behalf of the New Zealand steel industry that these tariffs if introduced [would] not apply to them

"We are of course a traditional partner of the United States, so we would be submitting to them that they shouldn't be catching New Zealand steel exports in a regime like that if they introduced it."

He said that in any case, New Zealand does not subsidise its steel industry so any tariff based on government subsidies would not apply to exports.

A spokesperson for New Zealand's aluminium smelter earlier said less than 2 percent of the aluminium produced at Tiwai Point was exported to the US, with most going to the Asia-Pacific market.

International criticism

The International Monetary Fund (IMF) has joined criticism of the plan, which would impose a 25 percent tariff on steel imports and 10 percent on aluminium.

It said others could follow the US president's precedent by claiming tough trade restrictions were needed to defend national security.

World Trade Organization Director General Roberto Azevedo said: "A trade war is in no one's interests".

Canada, the largest supplier of steel to the US, said tariffs would cause disruption on both sides of the border.

Canadian prime minister Justin Trudeau told reporters in Ontario he was "confident we're going to continue to be able to defend Canadian industry".

However, Mr Trump had doubled down on his moves, saying in a tweet that trade wars are good and easy to win.

"When a country (USA) is losing many billions of dollars on trade with virtually every country it does business with, trade wars are good, and easy to win," Mr Trump tweeted.

It is one of several countries that have said they will consider retaliatory steps if the president presses ahead with his plan next week.

A Chinese foreign ministry spokesman said: "If all countries followed the example of the United States, [it] will undoubtedly result in a serious impact on the international trade order."

Kosei Shindo, chairman of the Japan Iron and Steel Federation, said that the move would "create a negative chain reaction affecting not only steel but also other products considered to have national security implications".

Many US companies also expressed alarm, including beer brewers, which use aluminium for canned beverages.