The lead investor in a South Korean aluminum company that has challenged Commerce Department penalties on certain exports from South Korea to the United States made a $2 million payment last year to President Trump’s holding company.

The payment by the parent company, Base Group, was revealed for the first time in Mr. Trump’s annual financial disclosure form released in late June.

The document offered only a cryptic explanation for the payment, stating that it was part of a “letter of intent” and a “nonrefundable development fee.” In statements to The New York Times, the company and the Trump family said the payment relates to a still-unannounced golf course project.

Base Group has spent nearly a decade courting the Trump family, exclusively selling Trump-branded wine in South Korea and, more recently, hosting Mr. Trump’s son Eric at its Seoul headquarters.

The topic at the February gathering, according to a company executive: ways to increase trade between South Korea and the United States.

The efforts by Base Group to build ties with Mr. Trump and his family come as its corporate affiliate, Korea Aluminium, has curbed exports to the United States after the Commerce Department concluded that a group of South Korean companies circumvented trade duties on Chinese-made aluminum.

The New York Times found no evidence that Mr. Trump or a member of his family had intervened with U.S. officials on behalf of Base Group or Korea Aluminium. Base Group also disputed that it had violated any U.S. trade rules.

Alan Garten, the chief legal officer for Trump Organization, said in a statement that the payment was not related to the trade dispute.

“We have been in the golf, hospitality and real estate business for decades and have entered into transactions with countless companies around the world,” Mr. Garten said in the statement. “Any suggestion that this transaction was driven by anything other than legitimate business considerations is pure fiction.”

Still, the financial ties between the president and the South Korean company illustrate the minefield Mr. Trump has created by maintaining personal financial ties with nearly 30 different business ventures with foreign counterparts worldwide — unlike any other president in modern American history.

And it demonstrates how Mr. Trump is now benefiting from deals with foreign companies whose fortunes are affected by the decisions of his administration.

A White House spokesman said that Mr. Trump had not been involved in the trade dispute.

“There are no conflicts of interest, and the only special interest guiding the Trump administration’s decision-making is the best interest of the American people,” Kush Desai, a White House spokesman, said in a statement.

The Base Group payment is a small piece of at least $125 million in payments Mr. Trump’s holding company collected last year directly from foreign sources in several countries, including Britain, India, Indonesia, Ireland, Oman, the Philippines, Qatar, Romania, Saudi Arabia, South Korea, Turkey, Vietnam and the United Arab Emirates.

The total value of these deals is small compared with other sources of Mr. Trump’s 2025 revenue, such as cryptocurrency deals, which alone earned the president $1.4 billion last year.

But historians and former government officials interviewed by The Times said these kinds of direct financial entanglements by a president with foreign entities — and in some cases with foreign governments — had never happened at anything close to this scale.

Most presidents in American history have taken steps to avoid even an appearance of a conflict. George W. Bush sold his stake in the Texas Rangers baseball team as he was considering a presidential run. President Reagan liquidated his stock holdings, and Calvin Coolidge was so concerned about the appearance of a conflict, he did not even want to own a home.

“I never encountered anything like this,” said Peter J. Wallison, who served as White House counsel and at the Treasury Department during the Reagan administration. “It just creates conflicts of interest, and it makes it difficult for a president to make decisions, or it might affect his decisions, and that is problematic.”

Before starting his first term, Mr. Trump and his family vowed not to sign any new foreign deals while he was at the White House. But he dropped that pledge for his second term, arguing that his family had lost out on too many deals while still being criticized for foreign projects that had started before Mr. Trump was first elected.

Last year, Mr. Trump’s family signed new business deals in the Middle East, Europe and even a plan for a new resort hotel in the Maldives. In most cases, payments are tied to specific projects, such as luxury towers in Dubai that were announced last year.

The South Korean company and its top executive have sought to build a relationship with Mr. Trump and his family at least since he entered the White House in 2017.

That year, a Base Group subsidiary named Keumyang International started to import wine produced at the Trump vineyard in Virginia, an agreement that is still in place. Trump wine was served at a dinner Mr. Trump had in October with President Lee Jae Myung of South Korea during a trip to Asia.

More recently, the company’s chairman, Kim Sung-jip, traveled to Washington for Mr. Trump’s second inauguration in 2025 and then took another trip last spring to Trump National Doral golf club near Miami, where he met with Eric Trump.

This year, Mr. Kim hosted Eric Trump in South Korea in February for a series of meetings, including a dinner with top executives of other major South Korean corporations such as SK Networks, a technology company, and Hana Bank, one of the country’s largest financial institutions, according to local media coverage of the event.

At the gathering, they discussed ways to expand trade and business deals between the two countries, Kihyung Kang, executive director of Base Group, told The Times.

Mr. Garten, asked if the trade dispute had come up during the visit, said Eric Trump and other Trump Organization executives had “never had any discussions whatsoever regarding any government matters, trade issues, regulatory proceedings.”

While in South Korea in February, Eric Trump also visited a golf course site that a local government was promoting for the construction of a possible hotel and entertainment complex, according to a statement from local government officials there. The Trump Organization has 11 domestic golf properties, another five outside the United States and several others under construction.

Base Group, in a statement, said it had “an opportunity to acquire” a “world-class golf course” and it decided it would partner with the Trump family’s company.

“The Trump Organization owns and operates some of the finest golf and resort properties around the world,” the company said. “There was no other partner that could produce on the level and quality that a club like this would demand.”

The company said there was no relationship between the golf project and the trade dispute relating to Korea Aluminium, which sells foil used to package prescription drugs, ice cream cone containers and dozens of other products.

Korea Aluminium is owned by a construction company called Camus E&C. Base Group, a holding company, has a controlling stake in Camus, financial filings show.

The trade dispute dates to at least 2022, when the Biden-era Commerce Department announced it was opening an investigation into South Korean companies that appeared to be circumventing trade duties on Chinese-made aluminum by sending metal products based on it to the United States.

The company and other South Korean aluminum exporters aggressively challenged the accusation, arguing that they had “significant expertise and decades of knowledge” making distinctive aluminum products.

The federal government had previously concluded China was unfairly subsidizing its own aluminum industry and “dumping” its products at artificially low prices into the United States. The department suspected that China was trying to circumvent this punishment by diverting its product through South Korean companies, a finding it substantiated in 2023.

The Commerce Department moved in 2025 to impose a separate tariff on certain imports to the United States by South Korean aluminum suppliers, including Korea Aluminium.

These moves by the Commerce Department hurt Korea Aluminium’s sales, the company said.

“Our exports of AL-FOIL to the United States plummeted due to the impact of heavy U.S. anti-dumping duties on raw materials from China,” Korea Aluminium’s parent company, Camus, stated in its most recent annual report released in March, a claim repeated in other company documents.

Ms. Kang, the executive director of Base Group, said in an interview that the company had stopped exporting to the United States. Separately, the company said, it only sends aluminum products to the United States that are made from non-Chinese raw materials.

As recently as last month, the Commerce Department disclosed that it had received a request by an American aluminum trade group to extend the higher tariffs on importers including Korea Aluminium. There was no mention of the financial ties to Mr. Trump and his family. The agency’s docket shows no response so far by Korea Aluminium.

A preliminary review by the agency, summarized in a document released last week, suggests that agency staff agrees with the U.S. aluminum companies, who assert that Chinese aluminum is still being improperly dumped into the U.S. market and that it is considering increasing import tariffs against Korea Aluminium if it sends Chinese-made aluminum to the United States. No final action has been taken on the matter.

Mr. Desai, the White House spokesman, and Emily Davis, a spokeswoman at the Commerce Department’s International Trade Administration, both said that the review of the claims against Korea Aluminium have not been influenced by the White House.

“The Department of Commerce’s trade remedy proceedings are quasi-judicial, apolitical and administered according to strict statutory requirements,” Ms. Davis said in a statement. “At no time was there any political interference. Any suggestion to the contrary is baseless and defamatory.”

Barry Appleton, an international trade lawyer and law professor at New York Law School, said that he saw no evidence that Korea Aluminium was receiving favorable treatment. But Mr. Trump’s financial connection to the South Korean company is still a problem, he said, because as president he effectively maintains authority over the process.

“The Constitution was built on the presumption that presidents would always step away from any situation where there could be a sense of conflict,” Mr. Appleton said. “That gives faith to the public, so the public does not have to second guess if the president is acting in his financial self-interest. That is an open question here.”

Andrea Fuller contributed reporting.