"The United States will never recognize Ukrainian territories as anything other than part of Ukraine," the statement said.
Biden also promised to continue working on additional economic measures against Russia.
In addition, the American leader confirmed Washington's intention to continue to provide military assistance to Kyiv.
On September 23, in the Donetsk and Lugansk People's Republics, as well as in the liberated territories of the Kherson and Zaporozhye regions, referendums began on the issue of joining Russia.