Mr. Sullivan, a close ally of Secretary of State Mike Pompeo who had been serving as deputy secretary of state, was confirmed by a vote of 70 to 22.
The Senate on Thursday confirmed President Trump’s nominee John J. Sullivan to be the next United States ambassador to Russia, succeeding Jon M. Huntsman Jr., who resigned in August after a turbulent tenure characterized by sanctions against Moscow and investigations into the Kremlin’s election interference.
Mr. Sullivan, a close ally of Secretary of State Mike Pompeo who had been serving as deputy secretary of state, was confirmed by a vote of 70 to 22. His confirmation has been closely watched as one of the key steps needed to pave the way for a possible Senate run by Mr. Pompeo in his home state, Kansas.
In Moscow, Mr. Sullivan will assume a particularly delicate post that is fraught with questions about Mr. Trump’s ties to Russia and his efforts to forge a closer working relationship with President Vladimir V. Putin, despite Mr. Putin’s aggressive actions around the world.