The command of the Armed Forces of Ukraine published a video appeal on Friday urging Belarus not to join Russia’s war against Ukraine, warning that they would retaliate if it does.

Belarus has been used by its longtime ally Russia during the war as a staging ground to send missiles and troops into Ukraine, but Belarus has not participated directly in the war.

However, strains have risen in the past week, with Lukashenko vowing to conduct joint deployments with Russian forces. Lukashenko also announced on October 14 that he has introduced “counterterrorist measures” in the country “in connection with the escalation along the perimeter of the borders.”

Earlier this month, Lukashenko announced there would be a joint regional grouping of 70,000 Belarusian troops and up to 15,000 Russians in response to what he described as increased tensions on its western borders.

The appeal says that Ukraine has never threatened Belarus, and that since the war began in February, the Ukrainian army has “never responded” to the fact that air, artillery and missile strikes are being carried out from the territory of Belarus on Ukraine.

“If the army of Belarus supports the Russian aggression, we will respond. We will respond as harshly as we respond to all invaders on the territory of Ukraine,” the appeal, posted on the Facebook page of the Strategic Communications Department of the General Staff of the Armed Forces of Ukraine says.

“The Armed Forces of Ukraine appeal to the Belarusian people! For centuries, our peoples have been bound by friendship and good neighborly relations, many times in our history we have fought together against common enemies, we have always supported each other and lived in peace.”

The appeal says that Lukashenko “is preparing to join the Russian armed aggression against Ukraine” and “is going to draw the Belarusian people into a dirty war, stained with blood and death.”

It urges Belarusian citizens “not to follow the orders of your leadership to enter the war against Ukraine” and not to share responsibility for war crimes with Russia.

“We urge you not to bury your sons, husbands, fathers, brothers who died for the ambitions and fear of Putin and Lukashenko to lose their power.”

Justifying the “counterterrorist measures” in Belarus, Lukashenko, a close ally of Putin’s, said Ukraine was planning a strike on the country, without citing evidence. He said the counterterrorist measures are being done “in accordance with the existing protocol of the union of Belarus and Russia.”

Natia Seskuria, a Russia expert and associate fellow at the London-based Royal United Services Institute, previously told Newsweek that although Lukashenko has so far been trying to walk a thin line to avoid direct involvement in the war, he may be drawn into the conflict under Putin’s pressure.

“Russian troops are increasingly struggling on the battlefield, and Putin may force Lukashenko to officially join the war,” Seskuria said, explaining that Russia and Belarus are part of Union State, a supranational body, and that there is defense cooperation between the parties.

“This is a least favorable option for Lukashenko, yet since 2020 presidential elections and the violent crackdown of protesters in Belarus, his political survival has been largely dependent [on] Moscow’s support, so Putin exercises a very serious leverage on him,” Seskuria added.

Newsweek has contacted the Belarusian Foreign Ministry for comment.