Marjorie Taylor Greene and Donald Trump Jr have accused President Joe Biden of trying to start World War III after he gave Ukraine the green light to use US-supplied long-range supersonic missiles to strike inside Russia for the first time.

The Biden administration’s granting of Kyiv’s request to use the ATACMS missiles outside of its own borders marks a change in stance in the president’s final days in office, before President-elect Donald Trump – who has indicated he will limit US support for Ukraine – returns to the White House in January.

The MAGA representative and Donald Trump’s eldest son lashed out at Biden’s decision in fiery posts on X, Independent reported

“On his way out of office, Joe Biden is dangerously trying to start WWIII by authorizing Ukraine the use of U.S. long-range missiles into Russia,” Greene, who is among the Republicans who want to cut US aid to Ukraine, posted on Sunday.

“The American people gave a mandate on Nov 5th against these exact America last decisions and do NOT want to fund or fight foreign wars.

She concluded: “We want to fix our own problems. Enough of this, it must stop.”

Trump Jr – who last week told Ukrainian President Volodymyr Zelensky that his “allowance” is up now that Trump is returning to the White House – accused Biden of attempting to tarnish his father’s legacy by placing the US on the brink of conflict before he takes office.

“The Military Industrial Complex seems to want to make sure they get World War 3 going before my father has a chance to create peace and save lives,” Trump Jr said.

“Gotta lock in those $Trillions. Life be damned!!! Imbeciles!”

The move marks a major policy shift after Russia’s warning that it would regard Kyiv’s authorization to use US-made missiles “as a major escalation.” Russian President Vladimir Putin previously told Ukraine’s Western allies that such a move would represent NATO’s “direct participation” in the war.

At least two Russian legislators also warned that the US move risks another world war.

“I have a great hope that [Donald] Trump will overcome this decision if this has been made because they are seriously risking the start of World War III which is not in anybody’s interest,” said Maria Butina, a member of Putin’s party who was previously convicted of acting as an unregistered foreign agent of Russia within the US.

In an interview with Russia’s state news agency TASS, Vladimir Dzhabarov, first deputy head of the Russian upper house’s international affairs committee, described Biden’s decision as “unprecedented” while also warning of a possible global conflict. Dzhabarov said such an action would receive a swift response.

Biden’s decision comes with just 64 days left in the White House.

Trump meanwhile has criticized the Biden administration for spending more than $64bn in providing security assistance to Ukraine since Russia’s invasion of the nation in February 2022, according to figures from the US Department of State.

He has pledged to limit American support for Ukraine and end the war as soon as possible, even claiming on the campaign trail that he could do so in just a single day. It is unclear how he plans to do so.

He has pledged to limit American support for Ukraine and end the war as soon as possible, even claiming on the campaign trail that he could do so in just a single day. It is unclear how he plans to do so.