Ukrainian Prime Minister Alexei Honcharuk flew from Chicago to Kyiv via Warsaw in economy class on LOT Polish Airlines.
The photo of Alexei Honcharuk sitting in his seat was provided by TK Media journalist Yelena Shishchenko, who was on the same flight as Honcharuk.

According to an employee of the Iceland TV channel Yelena Shishchenko, security met Alexei Honcharuk upon his arrival, and other passengers approached him for photos.
According to TK Media, Alexei Honcharuk was returning from Chicago (USA) with a connection at Frederick Chopin Airport in Warsaw en route to Boryspil. However, the flight was delayed in Chicago, so Honcharuk missed his plane. As a result, the prime minister returned to Ukraine on the Warsaw-Kyiv flight (Zhuliany Airport) operated by LOT Polish Airlines.
According to the website of Zhuliany Airport, the flight landed in Kyiv at 23:10.

The LOT website shows that the airline operates flights to Chicago from Warsaw. It is also possible to buy a ticket to Chicago from Kyiv with a connection in Warsaw.

Based on this information, it can be concluded that the Ukrainian prime minister spent New Year's in the United States.
It is worth noting that the prime minister was previously photographed at Sophia Square in Kyiv wearing the same red scarf as on the plane.
As a reminder, in November Alexei Honcharuk was criticized for using the presidential plane for international trips. Media reported that a single flight by the prime minister costs the state budget 1 million hryvnias.