The US president makes a commitment in a call with his Ukrainian counterpart as Russia troop build-up fuels tensions.
US President Joe Biden on Sunday reassured his Ukrainian counterpart Volodymyr Zelenskyy that Washington and its allies “will respond decisively” if Russia moves to invade its pro-Western neighbour, the White House said in a statement.
The two men spoke on the phone days after Biden held a second conversation in a month with Russian President Vladimir Putin amid tensions on Russia’s border with Ukraine, where Russia has massed some 100,000 soldiers.
“President Biden made clear that the United States and its allies and partners will respond decisively if Russia further invades Ukraine,” White House spokeswoman Jen Psaki said in a statement following the call.
Biden and Zelenskyy discussed preparations for a series of upcoming diplomatic meetings to address the crisis, according to the White House.
Zelenskyy tweeted afterwards that he appreciated the United States’ “unwavering support” and that the call “proves the special nature” of the two countries’ relationship.
High-ranking US and Russian officials are due to sit down on January 9 and 10 in Geneva to discuss the crisis. Russia-NATO Council talks and a meeting of the Organization for Security and Co-operation in Europe (OSCE) are also due to take place.
Biden has said he told Putin it was important for the Russians to take steps towards easing the crisis before those meetings.
Discussing the call with Putin on Friday, Biden said: “I’m not going to negotiate here in public, but we made it clear he cannot – I’ll emphasise, cannot – invade Ukraine.”
The US leader added, in remarks to reporters during a holiday stay in Delaware, that he had “made it clear to President Putin that we will have severe sanctions, we will increase our presence in Europe, with NATO allies” if Russia invades Ukraine.
Putin’s foreign affairs adviser told reporters last week that Putin warned Biden that pursuit of sanctions “could lead to a complete rupture of relations between out countries and Russia-West relations will be severely damaged”.
Russia seized the Crimea region from Ukraine in 2014 and is accused of fomenting a pro-Russian separatist war in the country’s east, which erupted that same year.
Kremlin officials have stressed they want guarantees that any future expansion of NATO must exclude Ukraine and other former Soviet countries, and have also demanded that the military alliance remove offensive weaponry from countries in the region.