Exxon Mobil CEO Rex Tillerson, President-elect Donald Trumps pick for secretary of state, has expressed skepticism over the United States sanctions against Russia, as his company stands to reap enormous profits if they are lifted.

As secretary of state, Tillerson would play a major role in shaping the United States relationship with Russia going forward, and deciding whether to lift the sanctions put in place in response to Russias annexation of Crimea in 2014. Lifting the sanctions would give Russia more economic power.

Tillerson, who has run the worlds largest oil company since 2006, questioned the efficacy of sanctions multiple times since they were imposed by President Barack Obamas administration nearly three years ago.

According to The New York Times, Tillerson said in 2014 that his company generally does not support economic sanctions because we dont find them to be effective unless they are very well implemented comprehensibly, and thats a very hard thing to do. On a separate occasion, he said the company was looking forward to the sanctions being lifted.

And as Bloomberg notes , he also made many visits to the White House as the sanctions were being imposed and reportedly questioned whether the restrictions would give Exxon Mobils European competitors an advantage over U.S.-based companies.

Exxon Mobil has a huge interest in ending the sanctions, which put a halt to lucrative projects in the country the company has claimed the sanctions cost it up to $1 billion in revenue. In the meantime, Exxon Mobil and Tillerson have maintained strong ties with Russia and its president, Vladimir Putin . The company has already said it plans to return to its drilling project in the Russian Arctic once the sanctions are lifted.

Tillerson was a major driver of that relationship, rising up through the Exxon ranks by overseeing the companys Russian business interests. Hes personally negotiated deals with Putin and in 2013 was awarded Russias Order of Friendship award. On Monday, the Kremlin praised Trump for selecting Tillerson to lead the State Department, noting the executive carries out his duties in a highly professional way.

Tillerson also has a personal stake in Exxons success. According to The New York Times, Tillerson owns $218 million in Exxon Mobil stock .

Several lawmakers have expressed concern over Tillersons ties to Russia, calling for them to be a focal point in his Senate confirmation process.