“It was an honor to swear today John Sullivan as the new US ambassador to Russia. I’m sure that John will conduct successful work to strengthen cooperation and build constructive relations with Russia, ”the report said.

Honored to swear in John Sullivan as the new US Ambassador to #Russia today. I'm confident John will effectively lead the effort to strengthen cooperation and build a constructive relationship with Russia. pic.twitter.com/c8oFfwRDMx

- Secretary Pompeo (@SecPompeo) December 23, 2019

On December 13, Pompeo congratulated Sullivan on being appointed ambassador to Moscow.

In November, the US Senate Foreign Relations Committee approved the candidacy of Under Secretary Sullivan for the post of ambassador to Russia.