U.S. Sen. Ben Cardin of Maryland, the top Democrat on the Senate Foreign Relations Committee, announced his opposition Monday to President Donald Trump's secretary of state nominee.

Cardin had said previously he was "deeply troubled" by Rex Tillerson's appointment, but he did not signal whether he would oppose or support his confirmation.


In an interview Monday, Cardin said that he wouldn't lobby his colleagues to join him in voting against the former oil company boss. Cardin said worries about policy on Russia played into his decision.

"I am very concerned about whether he would maintain, let alone strengthen, the sanctions against Russia for their activities against this country," Cardin said of Tillerson.

Cardin also issued a statement Monday, and said Tillerson "equivocated" during committee questioning and placed "narrow business interests" ahead of national security concerns.

"After long and careful consideration, I believe Mr. Tillerson's demonstrated business orientation and his responses to questions during the confirmation hearing could compromise his ability as secretary of state to forcefully promote the values and ideals that have defined our country and our leading role in the world for more than 200 years," Cardin's statement said.

"I will therefore not be supporting his nomination with my vote in committee or on the Senate floor."

Tillerson was expected to receive Senate confirmation.

Florida Republican Sen. Marco Rubio, a Foreign Relations Committee member who ran for president, said Monday that he would support the former ExxonMobil chief executive despite some "reservations."