Poland's prime minister says his nation will not hesitate to shoot down objects that violate its airspace and pose a threat.

Estonia said three Russian fighter jets violated its airspace on Friday, adding to a sense among NATO leaders that Moscow is testing the alliance's readiness and resolve, with some urging a firm response. The United Nations Security Council is due to meet on Monday to discuss the incident.

Russia said on Monday the claim its jets violated Estonian airspace was false and designed to stir up tension.

The alleged incursion over Estonia came after more than 20 Russian drones entered Polish airspace on the night of September 9-10. Poland also said on Friday two Russian fighter jets violated the safety zone of the Petrobaltic drilling platform in the Baltic Sea.

'We will take the decision to shoot down flying objects when they violate our territory and fly over Poland - there is absolutely no discussion about that,' Donald Tusk told a news conference, adding that Poland will take a more cautious approach to situations that are less clear-cut.