The US announced on Friday sweeping new sanctions on Russia after President Vladimir Putin moved to formally annex additional Ukrainian territories in an action the Biden administration said was a "fraudulent" land grab.

In defiance of Putin's announcement, President Joe Biden said the US "will always honor Ukraine’s internationally recognized borders," and will continue to help Kyiv "regain control of its territory by strengthening its hand militarily and diplomatically."

Biden said the new tranche of sanctions on Russia, taken in coordination with US allies, "will impose costs on individuals and entities -- inside and outside of Russia -- that provide political or economic support to illegal attempts to change the status of Ukrainian territory."

"We will rally the international community to both denounce these moves and to hold Russia accountable," he said in a statement.

"We will continue to provide Ukraine with the equipment it needs to defend itself, undeterred by Russia’s brazen effort to redraw the borders of its neighbor. And I look forward to signing legislation from Congress that will provide an additional $12 billion to support Ukraine," he added.

Biden was referring to a stopgap spending bill that the House of Representatives is poised to pass on Friday that includes billions of dollars in additional funding for Ukraine.

Putin earlier on Friday announced the annexation of four Ukrainian regions -- Donetsk, Luhansk, Kherson, and Zaporizhzhia -- in violation of international law.

The territories amount to more than 90,000 square kilometers (34,749 square miles) or nearly 15% of Ukraine’s total area.

The new penalties being enacted by the US on Friday are wide-ranging, and encompass visa bans on 910 Russians, Belarusians and Russian proxies in Ukraine "for violating Ukraine’s sovereignty, territorial integrity, and political independence."

In addition, the Treasury Department is sanctioning the governor of Russia's Central Bank, as well as the wife and adult daughters of Russian Defense Minister Sergei Shoigu.​​​​​​​ The agency also announced the blacklisting of an additional 109 State Duma members, and 169 more members the Russian legislature's upper chamber.

The US previously sanctioned some Russian legislators.

In all, 14 individuals are being sanctioned for having supported Russia's defense sector, and the Commerce Department issued a new rule that adds 57 entities in Russia and Crimea to its blacklist, raising the total to 392.

Commerce also announced new guidance that it says sends "a clear warning" that US export controls can be applied to entities in third countries that seek to provide material support to the Russian and Belarusian militaries, including by helping them replenish key technologies and other items that have been prohibited by Washington and its allies.