Senate Minority Leader Chuck Schumer, D-N.Y., announced Friday that he will oppose Rex Tillerson's nomination as the next secretary of state, and cited his stance on Russia as the predominant reason for his opposition.

Schumer said that Tillerson, the former Exxon Mobil CEO, will make U.S. foreign policy "worse," and noted Tillerson's refusal to back sanctions or pledge to defend current sanctions against Russia. Schumer is also "unimpressed" by Tillerson's "grasp on foreign policy," and came away more worried after his meetings with the nominee.

"Mr. Tillerson's refusal to back new sanctions on Russia, and his refusal to even pledge to fully defend the current sanction regime is unacceptable but not surprising given his closeness to Vladimir Putin and the depth of Exxon's investment in Russia," Schumer said in a statement.

He also pointed to Tillerson's actions at Exxon Mobil, including his "alternative facts," as Schumer wrote, while attempting to deny that Exxon Mobil lobbied against sanctions against the Russians.

"These are not values that should define American foreign policy," Schumer said. "When I met with Mr. Tillerson, I came away more concerned about his and the President's grasp on foreign policy. I will oppose his nomination, and I encourage the full Senate to do the same."

The New York Democrat argued that Tillerson will not "lift a finger" to help fight climate change. Schumer's decision comes days after Tillerson cleared a hurdle by winning the support of Sen. Marco Rubio, R-Fla., and the Senate Foreign Relations Committee's 11-10 vote to advance Tillerson's process to the Senate floor.

The Senate is expected to advance Tillerson's nomination on Monday and confirm him later in the week.