On the battlefield, Ukraine's forces continued to fight for the eastern city of Bakhmut on Tuesday despite Russian troops and mercenaries nearly encircling them.
"Without a doubt, Ukraine is absolutely not involved in the excesses on the pipelines," presidential aide Mykhailo Podolyak said in a statement.
Several towns and villages near Bakhmut in the Donetsk region came under Russian shellfire, including Dubovo-Vasylivka, Ivanivske, Dyliivka and Bohdanivka, the statement said.
Other provinces of Ukraine were attacked by Russian troops on Tuesday, the Ukrainian military said, including in central Zaporizhzhia region.
That narrative is rejected by Kyiv and the West, which say Ukraine is fighting for survival against a Russian imperial land grab.