American intelligence officials have found Russian planning is under way for a possible military offensive against Ukraine that could begin as soon as early 2022.

The new intelligence finding estimates the Russians are planning to use an estimated 175,000 troops and almost half of them are already deployed along various points near Ukraine’s border, according to an official with US President Joe Biden’s administration who spoke on the condition of anonymity.

The official added that the plans call for the movement of 100 battalion tactical groups along with armour, artillery and equipment.

It comes as Russia has picked up its demands on Mr Biden to guarantee that Ukraine will not be allowed to join Nato.

On Friday he pledged to make it “very, very difficult” for Russian leader Vladimir Putin to take military action in Ukraine.

US intelligence officials have seen an increase in Russian propaganda through the use of proxies and media outlets to denigrate Ukraine and Nato ahead of a potential invasion, the White House official said.

Asked about the intelligence finding as he set out for the presidential retreat at Camp David on Friday evening, Mr Biden reiterated his concerns about Russian provocations.

Ukrainian soldiers sits in a fighting position on the line of separation from pro-Russian rebels
Ukrainian soldiers have spent years battling pro-Russian rebels (Andriy Dubchak/AP)

“We’ve been aware of Russia’s actions for a long time and my expectation is we’re going to have a long discussion with Putin,” he said.

The risks of such a gambit for Mr Putin would be enormous.

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

It remains unclear if Mr Putin intends to go through with what would be a risky offensive, they say.