The two politicians held informal talks ahead of their official bilateral meeting in Vilnius on Friday and a meeting between the prime ministers of the three Baltic countries and Poland in the Lithuanian capital later in the day.
Diplomats and advisers were not present at Thursday's meeting, which was not announced to the media.
"This was an informal meeting," Skvernelis told BNS on Friday, adding that it had been arranged on initiative of "both sides".
When asked why the meeting had not been publicly announced, he said, "Because it (the meeting) was rather unexpected as the Polish prime minister came straight from Brussels."
The Lithuanian prime minister said that the meeting had focused on key bilateral issues and regional projects, but gave no details.
Lithuania seeks Poland's support in synchronizing its power grid with the Western European system and in pressing Belarus over the Astravyets nuclear power plant under construction some 50 kilometers from Vilnius.
The Baltic countries have agreed that the grid synchronization will be done via Poland, but it is not clear yet how many interconnections will be needed. A final agreement is expected to be reached in June.
Lithuania, Latvia, Estonia and Poland are developing a joint European-standard gauge railway project named Rail Baltica.
A major boost to Lithuania's bilateral relations with Poland was given after the state railway company Lietuvos Geležinkeliai (Lithuanian Railways) and Orlen Lietuva, the Lithuanian unit of Poland's Orlen that owns the Mažeikiai crude refinery, last June signed a deal on oil product transport tariffs, ending a dispute over Poland's investments in Lithuania that had lasted for years.
Lithuania-Poland relations have been warming up in recent months. The two neighboring countries have exchanged high-level visits and Warsaw has considerably softened its tone regarding the situation of the Polish ethnic minority in Lithuania.
The Lithuanian and Polish prime ministers agreed on Friday to revive a bilateral commission to deal with ethnic communities' education issues.
Vilnius intends to back Warsaw in its dispute with the European Commission over Poland's controversial judiciary reform.