RIO DE JANEIRO — Members of the Home Overseas Affairs Committee stated Friday they have been “extraordinarily alarmed” by assertions that the American ambassador in Brazil had signaled to Brazilian officers they may assist get President Trump re-elected by altering their commerce insurance policies.

In a letter despatched Friday afternoon, Committee Chairman Eliot L. Engel demanded that the ambassador, Todd Chapman, produce “any and all paperwork referring or associated to any discussions” he has held with Brazilian officers in latest weeks about their nation’s tariffs on ethanol, an essential agricultural export for Iowa, a possible swing state within the American presidential election.

The committee’s letter was despatched in response to stories within the Brazilian information media this week saying that Mr. Chapman, a profession diplomat, made it clear to Brazilian officers they may bolster Mr. Trump’s electoral possibilities in Iowa if Brazil lifted its ethanol tariffs.

Eliminating tariffs would give the Trump administration a welcome commerce victory to current to struggling ethanol producers in Iowa, the place the president is in a close race with his Democratic rival, Joseph R. Biden Jr.

The Home committee stated it was opening an inquiry into the matter.

The State Division stated Friday afternoon in an emailed assertion that “allegations suggesting that Ambassador Chapman has requested Brazilians to assist a particular U.S. candidate are false.”

The assertion added: “The USA has lengthy been targeted on lowering tariff limitations and can proceed achieve this.”

The O Globo newspaper revealed a narrative on Thursday saying Mr. Chapman had underscored “the significance to the Brazilian authorities of retaining Donald Trump” in workplace. Mr. Bolsonaro, a far-right chief, has made nearer alignment with the Trump administration his prime international coverage precedence.

A competing newspaper, Estadão, published an article Friday saying its reporters independently confirmed that the ambassador framed his argument in opposition to tariffs in partisan phrases. The article stated the Brazilian officers who met with Mr. Chapman rejected the enchantment, declining to be drawn into the American presidential battle.

Neither article named its sources. However Alceu Moreira, a Brazilian congressman who heads the agricultural caucus, advised The New York Occasions in an interview that Mr. Chapman had made repeated references to the electoral calendar throughout a latest assembly the 2 had about ethanol.

He stated that Mr. Chapman didn’t explicitly urge him to assist the Trump marketing campaign or deliver up the competition in Iowa — however that the American ambassador did tie the ethanol situation to the election.

“He stated, ‘You already know, we’ve got elections in the USA, and that this is essential,’” Mr. Moreira stated, recounting their dialog. “He stated this 4 or 5 instances.”

Within the letter, Mr. Engel stated that if Mr. Chapman had pressured the Brazilians to assist the Trump marketing campaign, it might be a violation of the Hatch Act, a 1939 regulation that bars federal officers from partaking in sure partisan actions.

“These statements are fully inappropriate for a U.S. ambassador to make,” Mr. Engel, a Democrat from New York, wrote within the letter, which was additionally signed by Consultant Albio Sires, who chairs the Subcommittee on the Western Hemisphere, Civilian Safety and Commerce.

The letter referred to as on Mr. Chapman to “reassure Congress and the American those who our Ambassador to Brazil is really representing the pursuits of the USA and never the slender, political pursuits of President Trump.”

Selling favorable phrases for American industries overseas is a core precedence for American ambassadors. However American diplomats are reminded in election years to keep away from any actions which may moderately be construed as partisan.

The committee’s letter additionally took situation with Mr. Chapman’s protection of a video selling the Trump marketing campaign that Eduardo Bolsonaro, a federal lawmaker and a son of President Jair Bolsonaro, posted Sunday on Twitter.

The video ends with a slide that claims “Trump 2020: The Nice Victory.”

Requested concerning the video in an interview with O Globo, Mr. Chapman stated he noticed no drawback with Eduardo Bolsonaro’s endorsement.

“I’m a giant defender of freedom of expression,” Mr. Chapman advised the newspaper. “And everyone seems to be free to say who they like and who they’re in opposition to as they see match; I’m not going to inform somebody they’ll’t converse in favor or in opposition to my president.”

Mr. Engel and Mr. Sires, a Democrat from New Jersey, stated the ambassador ought to have responded in another way.

“Whereas Mr. Bolsonaro has the best to talk freely, it’s merely not applicable for sitting authorities officers — in any department of presidency — to advertise the campaigns of candidates in the USA,” the congressmen wrote. “We frankly imagine that you need to know higher.”

Eduardo Bolsonaro is the uncommon Brazilian official who has brazenly supported reducing ethanol tariffs for American sellers. In a video he posted last September, he stated taking successful on ethanol can be a boon for Brazilian exporters of meat and sugar by enhancing the possibilities of a free-trade settlement between the 2 nations.

“That might deliver so many advantages to us as Brazilians,” stated the youthful Mr. Bolsonaro, an ardent supporter of Mr. Trump who wore a “Make Brazil Nice Once more” baseball cap throughout a go to to the White Home final 12 months.

The USA has lengthy pushed Brazil to decrease tariffs on ethanol. These talks gained a brand new sense of urgency in latest months because the coronavirus pandemic led to plummeting demand, and American ethanol sellers have been squeezed by the commerce dispute between Beijing and Washington.

At present, American ethanol corporations can promote as much as 750 million liters of ethanol to Brazil per 12 months with out paying tariffs. Any gross sales past which might be topic to a 20 % tax. The Brazilian authorities raised the tariff-free cap final September from 600 million liters — a gesture meant to present Brazilian sugar producers larger entry to the American market.

Mr. Trump hailed that transfer, calling it “nice progress for our Farmers.”

However Washington didn’t make good on the sugar entry, which left the Brazilians feeling embittered.

The present ethanol tariff framework is about to run out in August. If the 2 nations don’t attain a deal, Brazil will apply a 20 % tax to all ethanol imports, a blow to an business that’s pleading for presidency bailouts.

Mr. Moreira, the Brazilian congressman who heads the agricultural caucus, stated he advised Mr. Chapman that Brazilian politicians additionally had political concerns to think about, given coming municipal elections in September. Ethanol producers in Brazil’s northeast states would look dimly on tariff guidelines that put them at a aggressive drawback.

“Is the ethanol producer essential electorally talking? Sure, essential,” Mr. Moreira stated. “We very very like the American individuals, however we like our individuals extra.”

Congressman Arnaldo Jardim, who leads a Brazilian congressional bloc that helps ethanol producers, stated Mr. Chapman has been negotiating with a way of urgency because the deadline approaches.

“Let’s simply say he’s placing strain,” on Brazilian officers, stated Mr. Jardim, including that he had not personally met with the ambassador about this situation, however usually speaks to a number of officers who’ve. “He’s saying that that is paramount for the USA and paramount for Trump.”

Orlando Ribeiro, who heads the division of business and worldwide relations at Brazil’s Ministry of Agriculture, stated that negotiators had hoped to achieve a deal on ethanol tariffs earlier than the August deadline that took into consideration the pursuits of all stakeholders.

Barring that, he stated he feared Mr. Trump and Mr. Bolsonaro might hash out a deal over the cellphone on the final minute.

“What might occur is that on the eve, Trump might name Bolsonaro and so they may resolve to raise all” tariffs, he stated.