He announced the sum of 137 billion zloty ($33 billion) at the opening of this year's edition of the region's biggest trade fair for military equipment, the MSPO in Kielce, Poland.

"When we see the emerging danger beyond our eastern border... we know perfectly well -- history and experience has taught us this -- that any price is worth paying to ensure that Poland is free, sovereign, independent and that Poles can live in safety," Duda said.

"Next year, we plan to spend 137 billion zloty on defence. That is more than four percent of our GDP," he added, quoted by the Polish news agency PAP.

That is an increase on the four percent of GDP Poland had pledged to spend on defence this year and much more than the 2 percent agreed by NATO allies.

Poland has shown itself to be a staunch ally of Ukraine ever since Russia's invasion last year.

More recently, Warsaw has also been sounding the alarm on threats that it says its other neighbour to the east -- Belarus -- poses, warning against "provocations" especially involving the Wagner mercenary group currently based there.

Warsaw has signed multiple arm deals, including with the United States and South Korea, from whom it ordered K2 "Black Panther" tanks and K9 howitzers.

Last month, the US approved a $12 billion sale of Apache attack helicopters to Poland, in another example of Warsaw's bid to boost its military capabilities in light of Russia's war in Ukraine.

In June, Poland received a first shipment of US-made advanced Abrams tanks. It had ordered a total of 366 tanks.

Poland also announced in April that it had signed a pound1.9-billion ($2.4-billion) air defence deal with the UK arm of Europe's MBDA, which will provide missiles and missile launchers.