BORIS Johnson has warned Vladimir Putin against making a “massive strategic mistake” in Ukraine on a visit to the country today.

The Prime Minister met with Ukrainian President Volodymyr Zelenskyy this afternoon in Kyiv to discuss the growing tensions on the border.

Foreign Secretary Liz Truss previously warned that the UK would impose the strictest sanctions upon Russia if it took any further action against Ukraine.

Ms Truss was unable to join Mr Johnson on today’s visit having tested positive with Covid yesterday.

Speaking at a press conference in the Ukrainian capital this afternoon, Mr Johnson said any further invasions by Russia would be "a disaster".

He said:" It goes without saying that a further Russian invasion of Ukraine would be a political disaster, a humanitarian disaster, and, in my view, also for Russia [and] for the world, a military disaster as well.

"And the potential invasion completely flies in the face of President Putin's claims to be acting in the interests of the Ukrainian people." 

He said the UK and allies were ready to launch sanctions against Russia “the moment the first Russian toecap crosses further into Ukrainian territory”.

The Prime Minister said: “We have done all this and prepared all this not as a show of hostility towards Russia, but as a demonstration that we will always stand up for freedom and democracy and Ukrainian sovereignty in the face of aggression.”

Mr Johnson said the people of Ukraine had an “inalienable right to choose how they are governed and indeed which organisations they aspire to join”.

He added: “It is vital that Russia steps back and chooses a path of diplomacy, and I believe that is still possible, we are keen to engage in dialogue, of course we are, but we have the sanctions ready, we’re providing military support, and we will also intensify our economic cooperation.”

In a joint statement from Mr Johnson and President Zelensky' offices, the pair “warned that any further Russian incursion in Ukraine would be a massive strategic mistake and have a stark humanitarian cost.”

They also discussed how the two countries could “work together to strengthen Ukraine’s security and ability to defend itself.”

The joint statement continued: “The leaders also expressed their commitment to strengthen Ukraine’s energy security and support its efforts towards the green transition.”

Mr Johnson announced he would provide £88m in aid to Ukraine to help build “resilience and reduce reliance on Russian energy supplies.”

He also stressed the UK’s “unwavering commitment” to the country’s “sovereignty, independence and territorial integrity within its internationally recognised borders”, according to the statement.

It continued:” The United Kingdom stands shoulder to shoulder with Ukraine in the face of ongoing Russian aggression, which threatens regional peace and security and undermines the global order. “The two leaders emphasised that it is the right of every Ukrainian to determine their own future.”

Mr Johnson is expected to speak to President Putin tomorrow where it is thought he will again urge the leader to dial down the aggression.

A planned call yesterday had to be scrapped as Mr Johnson was defending himself to MPs in the Commons over the partygate row.