South Korea has joined with the vast majority of the world to condemn Russia’s attempted annexation of territory within Ukraine:

The South Korean government said Saturday it does not recognize Russia’s recent annexation of Ukrainian territory as legitimate while strongly condemning Moscow’s invasion of the eastern European country.
On Friday, Russian President Vladimir Putin signed treaties to annex four regions in Ukraine, following referendums in the territory late last month.
“The Korean government strongly condemns Russia’s armed invasion against Ukraine as a violation of the principles of the U.N. Charter,” foreign ministry spokesperson Lim Soo-suk said in a statement.
“The Korean government does not recognize the referenda held in Donetsk, Luhansk, Zaporizhzhia, and Kherson and Russia’s annexation of the Ukrainian territory as legitimate.”
Yonhap
You can read more at the link, but areas that Russia is claiming in this annexation have already been liberated by Ukraine. This includes Russia’s embarrassing defeat this weekend in the logistical hub of Lyman.