Putin officially annexes four occupied Ukraine regions, hints again at use of nuclear weapons

Russian President Vladimir Putin on Friday officially declared four regions of occupied Ukraine part of Russia.

The announcement and related ceremony for the annexation were announced Thursday, following a recent voter referendum in the four regions that Western officials called a "sham."

At a ceremony Friday at the Kremlin, Putin vowed to use "all available means" to defend four regions being annexed, a statement being perceived as the Russia leader repeating his recent nuclear threat. 

“There are four new regions of Russia,” Putin also said, according to a translation and reported by CNBC.

The four regions are Luhansk and Donetsk, Kherson and Zaporizhzhia. 

Western leaders say the annexation is a violation of international law.

The balloting took place over roughly four days this past weekend, with Russian officials saying participation and support for the annexation was over 90%. 

"The results are known, well known," Putin also said Friday.  He also argued the results reflect the will of millions of people, saying they have the right to self-determination.