He posted a photo from Kyiv's railway station and wrote, "Good afternoon from Kyiv."
Poland's Foreign Ministry said Sikorski's visit was a show of support for Ukraine amid Russian aggression, Polsat News reported.
"This is a show of support for Ukraine, which is fighting for survival. The more Russia attacks, the more we need to support Ukraine," ministry spokesperson Maciej Wewiór said.
During Sikorski's visit to Kyiv on Sept. 11, Russian drones struck gas stations in the city's Obolonskyi and Dniprovskyi districts. At least four people were injured in the Obolonskyi district.
Kyiv Mayor Vitali Klitschko also reported that drone debris fell on a vehicle and that a fire broke out in a nonresidential area.