Washington, Mar 6 (IANS): Top Republican lawmakers including House Speaker Paul Ryan have raised concerns about President Donald Trump's plan to impose tariffs on metals fearing that it could pave the way for a "trade war", the media reported.

"We are extremely worried about the consequences of a trade war and are urging the White House to not advance with this plan," Ryan's spokeswoman AshLee Strong said in a statement on Monday.

"The new tax reform law has boosted the economy and we certainly don't want to jeopardise those gains."

Last week, Trump announced that the US planned to impose 25 per cent of tariff on steel imports and 10 per cent for aluminium, as these imports threaten the US national security.

Asked about Ryan's comments, Trump told reporters later on Monday: "No, we're not backing down."

Two Republican aides told CNN that leaders were not ruling out legislative action later on, but at this point the focus is on lobbying Trump to reconsider the move altogether, or to just focus on much narrower action.

Leaders of the House Ways and Means Committee have drafted a letter to Trump expressing concerns about "the prospect of broad, global tariffs on aluminium and steel imports", according to Lauren Aronson, spokeswoman for the committee Chairman Kevin Brady.

"As the two Chairmen have reinforced, the Administration and Congress must work together on trade policies that build off the momentum of the President's tax cuts, which is why any tariffs should be narrow, targeted, and focused on addressing unfairly traded products, without disrupting the flow of fairly traded products for American businesses and consumers," Aronson said in a statement.

Earlier on Monday, Ryan's office blasted out a CNBC article that linked a drop in the markets to Trump's planned tariffs.

In the wake of the President's announcement, Republicans have not been shy about their displeasure with the administration's decision.

The second ranking Republican in the Senate, Senator John Cornyn, described Trump's tariffs as "premature" and suggested the Senate's Finance Committee hold hearings on the issue.

"I think everyone is understandably concerned about what is going to happen next," John Cornyn told CNN.

"I guess the President is going to have to actually order the tariffs. I don't know how much it's going to be or how much impact that is going to have."

Senator John Thune, a South Dakota Republican, on Monday night said that Republicans were still looking at what legislative recourse they have to stop Trump's action on trade, but first they were trying to convince him not to go through with it.