"It can be most diverse. This depends on the suggestions that our military experts will give me," Putin told Russian broadcaster Rossiya 1.
The Russian president also stated that Moscow had proposed its strategic security guarantees to the United States and NATO to achieve a diplomatic result, Sputnik reported.
"We did not suggest (those guarantees) to blackball or stop something, in the context of this diplomatic process, but to achieve a diplomatic negotiations result that is legally set, as I said already, within the framework of the documents that we proposed. And we will work toward it specifically," Putin stated.
On December 17, Russia released draft security proposals that it wants to sign with the US and other NATO countries.
The proposals include mutual security guarantees in Europe, non-deployment of short- and intermediate-range missiles within reach to each other's territory, and NATO's non-expansion eastward onto former Soviet republics surrounding Russia.