WARSAW, June 29 (Reuters) - Poland expects the European Union to help it fund measures to strengthen its eastern border, a deputy minister said on Thursday, after Warsaw announced a tightening of security due to concerns over the presence of the Wagner group in Belarus.

Russian President Vladimir Putin's decision to offer troops from the private military company the choice of relocating to Belarus has led to fears among eastern NATO members that their presence will cause greater instability in the region.

On Wednesday the leader of Poland's ruling nationalists Law and Justice (PiS), Deputy Prime Minister Jaroslaw Kaczynski, said Poland believed that there could be around 8,000 Wagner troops already in Belarus.

He said Poland would take both temporary and permanent steps to strengthen the border, including boosting the presence of security forces and increasing fortifications.

Asked on Thursday whether Brussels should help Warsaw pay for such measures, Deputy Foreign Minister Pawel Jablonski said "Poland expects it".

"European solidarity means supporting countries threatened with destabilization," he told public radio. "These safeguards need to be increased."

Poland accuses Belarus of artificially creating a migrant crisis on the border by flying in people from the Middle East and Africa and attempting to push them across the frontier. Minsk has denied the accusation.

Kaczynski said on Wednesday that Wagner's presence in Belarus could mean "a new phase of hybrid warfare, a phase much more difficult than the one we have dealt with so far."

Kaczynski, who is widely viewed as Poland's de-facto ruler, appeared to take a stronger line on border security than President Andrzej Duda, who had spoken earlier in the day in Kyiv.

Duda said Poland would strengthen security on its border with Belarus if it needs to, but that the frontier is already tightly secured.