Prime Ministers Saulius Skvernelis of Lithuania and Mateusz Morawiecki of Poland held a "no tie" meeting at the Kalvarija border crossing to mark the lifting of internal border controls.
However, the two casually-dressed leaders skipped the usual handshake as they posed to journalists in front of a lineup of border guards.
"No handshake, unfortunately," Skvernelis said after a short conversation at the border.
The Lithuanian prime ministers told a news conference after their bilateral meeting that the measures taken by both governments had made it possible to "cope perfectly with the challenge" of the coronavirus pandemic.
"I'm glad that Poland and Lithuania, and our people, and our governments have managed to protect people's lives and support the economy and not to disrupt our social life. This is a great achievement for the governments of both Poland and Lithuania," he said.
Skvernelis underlined the need for "maintaining the strategic partnership between Lithuania and Poland" and called on voters to back politicians who support this partnership.
"We've had issues in our history. That's why I hope that the people of both Lithuania and Poland will support those political forces and politicians thanks to whose efforts we – both Poland and Lithuania– have strategic partners and excellent neighbors," he said.
Lithuania and Poland closed their borders to foreigners in mid-March in an effort to stem the spread of the coronavirus.
In mid-May, the two countries reopened their border to each other's citizens travelling for work, business or study.
Poland has recently reported a spike in new COVID-19 cases in coal mines.