The head of state, whose Baltic country neighbours both Belarus and Russia and will host next month's NATO summit, spoke after a state security council meeting to discuss Wagner's aborted revolt against the Kremlin.

After Prigozhin called off his troops' advance on Saturday, Moscow said the Wagner chief would leave Russia for Belarus and would not face charges.

"If Prigozhin or part of the Wagner group ends up in Belarus with unclear plans and unclear intentions, it will only mean that we need to further strengthen the security of our eastern borders," Lithuanian President Gitanas Nauseda told reporters.

"I am not only talking about Lithuania here, but without a doubt the whole of NATO," he said.

Nauseda added that Lithuania will devote more intelligence capabilities to assessing the "political and security aspects of Belarus".

Lithuania will host next month's NATO summit, and Nauseda said the general security plan for the meeting does not require changes following the Russian developments.

He said he believed Russian President Vladimir Putin could face even greater challenges in the future, adding: "The king is naked."

The Wagner rebellion marked the biggest challenge yet to Putin's long rule and Russia's most serious security crisis since he came to power in 1999.