Republicans have pleaded with Donald Trump to back away from a potential trade war after he threatened to impose tariffs on steel and aluminium imports.
A spokeswoman for Paul Ryan said the House Speaker was "extremely worried" about the proposed tariffs and urged the White House "to not advance with this plan".
Likewise, Republican leaders of the House Ways and Means Committee circulated a letter opposing Trump's plan.
And GOP congressional leaders suggested they may attempt to prevent the tariffs if the president moves forward.
Ryan's statement was something of a public rebuke to the president.
But asked to comment, White House press secretary Sarah Huckabee Sanders said, "Look, we have a great relationship with Speaker Ryan. We're going to continue to have one, but that doesn't mean we have to agree on everything."
Mr Trump has pledged to implement tariffs of 25 per cent on steel imports and 10% on aluminium imports.
The move has roiled financial markets, angered foreign allies and come under criticism from the president's own team.
White House economic adviser Gary Cohn warned against penalizing US allies and undercutting the economic benefits of Mr Trump's recent tax overhaul.