NATO Secretary-General Jens Stoltenberg says an upcoming "landmark summit" will enhance the alliance's defensive and deterrent presence in Poland and in the region, but decisions as to the number are still haven't been finalized.

Stoltenberg spoke Monday in Warsaw, which will host a July 8-9 NATO summit that will give security guarantees to Poland and other nations on its eastern flank concerned about Russia.

He said that several battalions will be placed in Poland, the Baltic States and elsewhere in the region that will raise NATO presence in troops, equipment, prepositioning and infrastructure.

Speaking alongside Stoltenberg, Polish President Andrzej Duda said it's crucial for the summit to show that NATO is united and shows internal solidarity in the face of threats from the East and South.