KYIV : The presence of Wagner troops in Belarus could pose a potential "threat" to the countries of the region, Polish President Andrzej Duda said Wednesday during a visit to Ukraine.

"It is difficult for us to exclude today that the presence of the Wagner Group in Belarus could pose a potential threat to Poland, which shares a border with Belarus, a threat to Lithuania... as well as potentially to Latvia," Duda told reporters in Kyiv.

Following a rebellion by the mercenary group, Russian President Vladimir Putin ordered that Wagner lose its heavy weaponry, and that its fighters either join the regular armed forces or accept exile in Belarus.

"The question arises: what is the purpose of this relocation?" said the Polish president.

"What are the real intentions of the Wagner Group forces, in other words, the Russian army, precisely in Belarus?

"Is it a form of potential threat precisely towards our countries, towards NATO countries, towards Poland?" Duda added, speaking next to his Lithuanian and Ukrainian counterparts.

NATO chief Jens Stoltenberg said Tuesday it was still too early to draw conclusions from the move to Belarus of Prigozhin and, likely, some of his forces. But he vowed that the alliance was ready to defend its members.

On Wednesday, Ukrainian President Volodymyr Zelensky said NATO had to send "a very direct" message in defence of the alliance.

"If the alliance is powerful... then NATO must unanimously tell the Polish and Lithuanian societies that if one foot of one Wagner fighter is on the independent territory of Lithuania or Poland, then all Wagner fighters will be destroyed," Zelensky said.

"And the Vilnius summit is a great platform to make such a very direct message," Zelensky added, referring to the NATO summit to be held in Lithuania on July 11-12.