This is part of a Russian disinformation campaign about Belarus based on recurring pro-Kremlin disinformation narratives, portraying the West as aiming to destabilise the situation in Belarus.
There is no evidence that "the West" in general, nor Poland or Lithuania in particular, tries to destabilise the situation in Belarus. Poland and Lithuania support the independence and territorial integrity of Belarus and they do not have any territorial claims against their neighbour.
The protests in Belarus were a reaction to the supposed results of the Presidential election in Belarus which took place on 9 August. The outcome is considered fraudulent by a large part of Belarusian society. The European Union has also stated that the elections were neither free nor fair. However, there is no evidence that the protests in Belarus are funded and organised externally.
On 19 August 2020, the European Council condemned the violence against peaceful protesters and announced that it would soon adopt a list of sanctions for those responsible for the violence in Belarus. "As the elections in Belarus were neither free nor fair, and did not meet international standards, the EU does not recognise the results presented by the Belarus authorities," was stated in one European Council press release.