By Staff, Agencies

US President Joe Biden on Friday warned Russia there will be "swift and severe" costs if Moscow uses "sham" referendums to annex more of Ukraine.

"Russia's referenda are a sham -- a false pretext to try to annex parts of Ukraine by force in flagrant violation of international law," Biden said in a statement. "We will work with our allies and partners to impose additional swift and severe economic costs on Russia."

"The United States will never recognize Ukrainian territory as anything other than part of Ukraine," he said.

Kremlin-held regions of eastern and southern Ukraine entered the second day of voting to become part of Russia on Saturday.

The vote will take place until Tuesday next week. Preliminary results are expected to be released by Wednesday.

The Donetsk and Lugansk People’s Republics [DPR and LPR] broke away from Ukraine shortly after the 2014 coup in Kiev. They are predominantly Russian-speaking and share a border with Russia. Moscow recognized them as independent states in February.

Russia currently controls Ukraine’s Kherson Region, as well as large parts of Zaporozhye Region, which were seized after Moscow launched its military operation in the neighboring country on February 24.