Russian President Vladimir Putin has forwarded accession treaties, which formalize integration of four Ukrainian regions into the Russian soil, to State Duma -- the lower house of the Russian parliament -- for ratification.
Putin submitted the treaties to the legislative body on Sunday, Russia's ITAR-TASS news agency reported.
"The State Duma is scheduled to review these documents on October 3, and the Federation Council (the upper house of the parliament) will review them on October 4," the agency reported.
Upon the parliament's ratification of the treaties, the foursome regions' borders would "become the new state border of the Russian Federation," the report added.
Putin signed the treaties on Friday during a ceremony attended by the leaders of the regions, namely Donetsk and Luhansk in eastern Ukraine and Kherson and Zaporizhzhia in the south of the ex-Soviet republic.
The regions had earlier voted overwhelmingly in favor of accession to the Russian Federation during separate referendums.
Ukraine and its Western allies, however, consider the votes to be a "sham."
The votes were held amid an ongoing Russian military offensive in Ukraine, which Moscow launched in February to defend Donetsk and Luhansk's Russian population against persecution by Kiev.
Also on Sunday, presidents of nine NATO countries condemned, what they called, Russia's annexation of the regions.
“We do not recognize and will never recognize Russian attempts to annex any Ukrainian territory,” the heads of state of the Czech Republic, Estonia, Latvia, Lithuania, Montenegro, North Macedonia, Poland, Romania, and Slovakia said in a statement.
Hungary was notably absent from the list amid efforts by President Viktor Orban to forge closer ties with Moscow. Albania, Bulgaria, Croatia, and Slovenia were also absent from the event.
The statement said the countries "encourage all [NATO] Allies to substantially increase their military aid to Ukraine,” it said. Russia has warned that providing Ukraine with arms would only protract the conflict.
The statement also backed Kiev's demand to join the United States-led military alliance. Moscow has, on numerous occasions, warned NATO against attempting to move closer to its doorstep.