“President Biden also made clear that the US will act firmly in defence of its national interests in response to Russia’s actions, such as cyber intrusions and election interference,” the White House said in a brief statement.

“President Biden emphasised the US’ unwavering commitment to Ukraine’s sovereignty and territorial integrity.

“The President voiced our concerns over the sudden Russian military buildup in occupied Crimea and on Ukraine’s borders, and called on Russia to de-escalate tensions,” it added.

The conversation was only the second between the two leaders since Biden became president on Jan 20 and it took place amid growing US and European concerns about Russian treatment of Ukraine.

Western officials say Russia has moved thousands of combat-ready troops to Ukraine’s borders this year, the largest massing of Russian troops since it seized Crimea from Ukraine in 2014.

Fighting has escalated in recent weeks in eastern Ukraine, where government forces have battled Russian-backed separatists in a seven-year conflict that Kyiv says has killed 14,000 people.

“President Biden reaffirmed his goal of building a stable and predictable relationship with Russia consistent with US interests, and proposed a summit meeting in a third country in the coming months to discuss the full range of issues facing the US and Russia,” the White House statement added.