Joe Biden and Vladmir Putin set for talks next week as tensions grow over Ukraine

US president Joe Biden and Russian counterpart Vladimir Putin will speak by telephone on Tuesday as tensions escalate over a Russian troop build-up on the Ukrainian border – seen as a sign of a potential invasion.

Kremlin spokesman Dmitry Peskov confirmed plans on Saturday for the much-anticipated call and said it will take place in the evening.

Russia is adamant that the US should guarantee that Ukraine will not be admitted to the Nato military alliance.

US intelligence officials, meanwhile, have determined that Russia has massed about 70,000 troops near its border with Ukraine and has begun planning for a possible invasion as soon as early next year, according to a Biden administration official.

The risks for Mr Putin of going through with such an invasion would be enormous.

US officials and former American diplomats say while the Russian president is clearly laying the groundwork for a possible invasion, Ukraine’s military is better armed and prepared today than in the past, and that sanctions threatened by the West would do serious damage to the Russian economy.

Mr Biden said on Friday: “What I am doing is putting together what I believe to be, will be, the most comprehensive and meaningful set of initiatives to make it very, very difficult for Mr Putin to go ahead and do what people are worried he may do.”

Ukrainian officials have said Russia could invade next month.