WASHINGTON, D.C. (AP/KCRG-TV9) -- Iowa's U.S. senators and representatives have banded together to urge President Donald Trump not to impose tariffs on imported aluminum and steel, for fear it would start a trade war.

The delegation, which included Sen. Joni Ernst (R), Sen. Chuck Grassley (R), Rep. David Young (R), Rep. Rod Blum (R), Rep. Dave Loebsack (D), and Rep. Steve King (R), sent a letter to the president warning him the tariffs could adversely impact Iowa's farmers and manufacturers.

"As Members of Congress who represent Iowa, we understand the importance of free and fair trade to Iowa’s strong agricultural economy," began the letter. "We urge you to carefully consider and analyze the economic costs and benefits of your plan to impose new tariffs on imported steel and aluminum."

The letter went on to say the state "is comprised of diverse industries which play a vital role in supporting not only Iowa’s economy but the entire U.S. economy."

When compared to the nation, the delegation pointed out Iowa is the second largest export state when it comes to agriculture, saying it shipped about $10 billion of exports abroad in 2015.

The group used China as an example, saying Iowa recently began exporting U.S. beef and has other major exports including corn, pork. and soybeans. China takes an estimated 60% of the state’s soybean production.

"As farmers have already faced several years of low commodity prices," said the letter, "any hit to demand would be devastating to their financial situations."

Trump reaffirmed his plans to place tariffs on steel and aluminum, Tuesday. He said at a White House news conference, "Trade wars aren't so bad."

The president was asked during a joint news conference if he would go through with his plans to impose a 25 percent tariff on steel imports and a 10 percent tariff on aluminum imports.

Trump said the U.S. has long been "mistreated" by trade deals and has been dealing with a massive trade deficit.

The Iowa delegation's letter comes as more and more members of the president's own party have risen in opposition to the tariffs, including House Speaker Paul Ryan.

The speaker is among the most outspoken GOP critics of Trump's plan.

Ryan says Trump is right to call out countries dumping metals and says there's "clearly abuse occurring."

But the speaker says there's a "smarter way to go" and Republicans are trying to convince Trump to "go after the true abusers without creating any kind of unintended consequences or collateral damage."

The Iowa delegation's letter ended by saying members of the group "recognize there is excess global capacity for steel and aluminum," but that "the overall impacts must be part of the administration’s calculus."

"We urge you, Mr. President," said the letter, "to reconsider this proposal given the consequences this will have on states like Iowa, rural communities throughout the nation, and on America’s farms."