President Joe Biden assured Ukrainian President Volodymyr Zelensky that the US and its allies will respond “swiftly and decisively” to any further aggression by Russia against Ukraine.

“President Biden made clear that the United States would respond swiftly and decisively, together with its allies and partners, to any further Russian aggression against Ukraine. The two leaders agreed on the importance of continuing to pursue diplomacy and deterrence in response to Russia’s military build-up on Ukraine’s borders”, - the White House said of the call.

In a tweet Sunday following the call, Zelensky said he and Biden discussed “security, economy, existing risks, sanctions and Russian aggression”.

The conversation with the Ukrainian president comes one day after Biden spoke with Russian President Vladimir Putin, where similarly warned that should Russia take action against Ukraine, the U.S., along with its allies, “will respond decisively and impose swift and severe costs on Russia”.