On Thursday, Russia called on Poland to reopen its border with Belarus, its ally, describing the closure as “destructive” and cautioning about potential repercussions.

Polish Prime Minister Donald Tusk declared the border with Belarus would be closed starting at midnight on September 12 (10 p.m. GMT on September 11) in reaction to the planned joint military exercises between Russia and Belarus.

“We urge Warsaw to reflect on the implications of such harmful actions and to reconsider its choice at the earliest opportunity,” said Maria Zakharova, a spokesperson for the Foreign Ministry, in a statement.

She noted that the border closure was intended to “justify a strategy of further escalating tensions in the heart of Europe.”

NATO members along its eastern flank—Poland, Lithuania, and Latvia—are under heightened alert due to the large-scale drills, which Tusk indicated aim to mimic the occupation of the Suwalki corridor, a critical area in Poland.

Typically conducted every four years, the 2025 edition of the Zapad exercises is the first to occur since the onset of the Ukraine conflict and is set to continue until September 16.

In January, Belarus announced that approximately 13,000 troops would participate in the exercises, but later in May reduced that figure by about half.

Zakharova criticized Warsaw for “demonstratively” disregarding the diplomatic efforts by Moscow and Minsk to relocate the exercise away from the Polish border and to scale down the number of troops involved.