Polish President Bronislaw Komorowski on Friday signed an amendment that guarantees funds for Poland's missile shield programme from next year until 2023.

The program will be integrated into the wider NATO project and will "send an important signal to all that Poland has its own means of defence," he said, quoted on the presidency's website.

Komorowski inked the amendment to a law on financing the armed forces at a military base in the northeastern village of Szypliszki, site of a powerful NATO radar.

Last month, Polish Foreign Minister Radoslaw Sikorski said Poland would spend 33.6 billion euros ($43.3 billion) to upgrade the army and "build up its deterrence forces".

"We will create our own air defence system. Our national missile shield, with the American shield, the elements of which will be on our territory by 2018 and will make up part of the NATO system," Sikorski told parliament.

The US said last month it would deploy 14 additional anti-missile interceptors in Alaska, up from the current 30, in response to mounting concerns about nuclear-armed North Korea.

The plan for Europe -- to counter a potential Iran threat -- envisages the deployment of dozens of SM-3 interceptors in Romania and Poland between now and 2018.

Moscow is strongly opposed to the plan, seeing it as a threat to its security, and demands to either be associated with it or receive guarantees it's not a target.

Having shed communism in 1989 before joining NATO in 1999 and the EU in 2004, Poland, a nation of 38 million has spent the last two decades updating its Soviet-era military hardware.

It is also the only EU member to have sustained growth amid both the global financial and eurozone crises, and spends round 1.95 percent of its gross domestic product on defence.