Energy giant ExxonMobil, while under the leadership of Rex Tillerson, President-elect Donald Trump’s pick for secretary of state, made deals with Iran, Syria and Sudan while these countries were under US sanctions as state sponsors of terrorism, according to US media reports.

According to USA Today, sales to these countries were conducted in 2003, 2004 and 2005 by the European-based Infineum, in which ExxonMobil owned a 50% share. This information was unearthed by American Bridge, a Democratic research group, citing Securities and Exchange Commission (SEC) filings.

The 2006 filings, cited by USA Today, show that “the company had $53.2 million in sales to Iran, $600,000 in sales to Sudan and $1.1 million in sales to Syria during those three years.”

Tillerson was a top executive at ExxonMobil for over a decade. He became senior vice president in 2001, later becoming president and director in 2004 before being named chairman and CEO in 2006, a position he’s held until Trump named him as future top diplomat.

ExxonMobil told USA Today that the transactions were legal because they were made though a European company and no US employees were involved in the deals.

“These are all legal activities complying with the sanctions at the time,” Alan Jeffries, ExxonMobil’s media manager at ExxonMobil, told USA TODAY. “We didn’t feel they were material because of the size of the transactions.”

“They [Infineum] have an independent management that operates the entity. And it’s not a US entity,” he said.

ExxonMobil’s dealings with these countries may become an issue during confirmation hearing for Tillerson, which are expected to begin on Wednesday.

New Jersey Senator Bob Menendez, the ranking Democrat on the Foreign Relations panel, said in response to the report that he was “deeply skeptical about Mr. Tillerson’s actions as CEO of Exxon that were in direct contravention to express United States policies put in place to secure Americans and our country.”

“Finding loopholes to make lucrative business deals with geo-political adversaries, while showing no clear regard for US national interests, is not a resume builder for a prospective diplomat-in-chief,” Menendez said in a statement cited by USA Today. “This is one of the many issues I look forward to hearing more about during the upcoming confirmation hearings.”

Tillerson has also come under fire for his close ties to Russia and its president Vladimir Putin.

In this June 15, 2012, file photo, Russian President Vladimir Putin, left, and ExxonMobil CEO Rex Tillerson shake hands at a signing ceremony of an agreement between state-controlled Russian oil company Rosneft and ExxonMobil at the Black Sea port of Tuapse, southern Russia. (Mikhail Klimentyev/RIA-Novosti, Presidential Press Service via AP, Pool, File)

In this June 15, 2012, file photo, Russian President Vladimir Putin, left, and ExxonMobil CEO Rex Tillerson shake hands at a signing ceremony of an agreement between state-controlled Russian oil company Rosneft and ExxonMobil at the Black Sea port of Tuapse, southern Russia. (Mikhail Klimentyev/RIA-Novosti, Presidential Press Service via AP, Pool, File)

His hearing will thus provide a stage for critics of Trump’s affection for Moscow and his defense of Putin in the face of warnings from US intelligence about Kremlin cyber warfare.

The Democratic minority in the Senate will try to make life difficult for most of Trump’s nominees, and a handful of Republicans have raised concerns about Tillerson’s candidacy. If just three Republicans jump ship, 64-year-old Tillerson could be among the first and most high-profile victims of the spat, despite heavyweight players mobilizing in his support.

Until he stepped down from ExxonMobil on New Year’s Eve. Tillerson was also director of Exxon Neftegas, an affiliate that operates the Sakhalin-1 field in Russia’s Far East.

The US parent firm was chasing greater investments in Russia, including Arctic fields, and Tillerson was a familiar and popular figure in Moscow, winning his medal from Putin in 2012.

This made ExxonMobil under Tillerson a staunch opponent of US and international sanctions against Russia for its aggressive behavior in Ukraine, where it annexed the Crimea region.

He has placed his ExxonMobil stock holdings in a trust and promised to recuse himself from any issues where the firm’s worldwide holdings present a conflict of interest.