Mike Pompeo / REUTERS

"Pompeo just had a call with Ukraine's [President Volodymyr] Zelensky. Comes after he delayed his visit to Kyiv. He's now expected to go at the end of the month," journalist Christopher Miller said on Twitter on January 6, referring to a U.S. State Department readout of a recent phone call between the two officials.

Pompeo spoke with Zelensky to discuss postponement of his trip to Ukraine, the readout says.

"The two discussed the situation in the Middle East and the Secretary appreciated Ukraine's condemnation of the attack on the U.S. Embassy in Baghdad," it says.

Pompeo reiterated the strong U.S. support for Ukraine's sovereignty and territorial integrity and underscored U.S.-Ukraine long-term strategic partnership.

As was reported, Pompeo postponed his visit to Ukraine after an attack on the U.S. Embassy in Iraq on December 31. He was originally expected to arrive in Kyiv on January 3.