Poland's Foreign Minister Witold Waszczykowski said Russia is a greater threat to the world than the Islamic State (ISIS) because it has the potential to destroy countries.

Speaking at a recent security conference in Bratislava, Slovakia, Waszczykowski described Russia as an "existential threat" and called on NATO to immediately deploy troops to guard its eastern flank against Moscow's aggression, the Daily Mail reports.

He said he would appeal to NATO directly when the organisation holds its summit in Warsaw in July.

"We have existential threats and non-existential threats. Of course the Russian activity is kind of an existential threat because this activity may destroy countries," he said during a media conference.

"And we have non-existential threats like terrorists, like massive wave of migrants," he added. "It is a very important threat but it is not an existential threat for Europe."

Poland, one of Moscow's staunchest critics, was one of the first countries to express alarm when Russia annexed Ukraine's Crimea peninsula in 2014 and supported armed separatists in eastern Ukraine.

Waszczykowski expressed hope that the July NATO summit would "address an inferior level of security" on its eastern flank.

In 2014, the Polish Foreign Minister described the "offensive action" taken by Russian armed forces in the southern regions of Donetsk as an aggression by international law.

He called on NATO countries to deploy troops on NATO's eastern flanks to show Moscow the Western alliance's determination to defend its territory.

However, Russia has warned that the deployment of significant NATO forces close to its borders would violate the 1997 NATO-Russia Founding Act.