President Donald Trump is facing growing pressure from political and diplomatic allies as well as US companies to pull back from proposed steel and aluminium tariffs, although he said he would stick to his guns.
Inside the White House, there still appeared to be confusion about the timing and extent of the planned tariffs, which would hit allies like Canada and Mexico hard.
Efforts by Trump and US trade negotiators to link the NAFTA trade pact talks to the duties received short shrift from Ottawa and Mexico City.
Leading Republicans turned up the pressure on Trump, with House of Representatives Speaker Paul Ryan leading the charge. Ryan's home state of Wisconsin would be hit by proposed European counter-measures on Harley-Davidson motorbikes.
Business leaders are pressing for a meeting with Trump to brief him on the negative repercussions of the tariffs on companies that use steel and aluminium, a source familiar with the matter said.
The planned tariffs have hit world stock markets as investors worried about the prospect of an escalating trade war that would derail global economic growth.
"We're not backing down," Trump said during a White House meeting with Israeli Prime Minister Benjamin Netanyahu on Monday. "I don't think you're going to have a trade war," he added, without elaborating.
Canadian Prime Minister Justin Trudeau called Trump to tell him the tariffs would be an impediment to talks on updating NAFTA, a Canadian government official said.
Canada is the single largest supplier of steel and aluminium to the United States. In the call, Trudeau "forcefully defended" Canadian workers and industries, said the official, describing the conversation as constructive.
Earlier comments from Trump had stoked talk of a global trade war as he described them as easy to win, and issued a threat to German carmakers.
One of those, BMW, runs a plant in the United States that is the largest single autos exporter in the country and has created thousands of jobs.
Most responses to Trump's proposed tariffs have been targeted. The European Union said it would hit Harleys, bourbon and jeans, iconic American products.
China has been largely mum, urging caution, and both Canada and Mexico have stressed the targeted nature of any response.
Trump was expected to finalise the planned tariffs later in the week, although some observers familiar with the process said it could occur next week. The initial announcement by Trump last week came as a surprise.