An Essex man living in Ukraine has described feeling “worried and anxious” as his Ukrainian wife and son await approval from the UK visa office to flee the country.

Mounting tensions are nearly at breaking point as Boris Johnson warned that Vladimir Putin appears “bent on a full-scale invasion” and vowed to swiftly introduce the “first barrage” of sanctions against Russia.

Nathan Rossiter, 32 and from Essex, has spent most of the past seven years in Kharkiv – which is around 25 miles from the Russian border in northeast Ukraine – but has faced prolonged difficulty in securing a visa for his wife Lena and their five-year-old son, Leo.

Mr Rossiter said while he likes life in Ukraine, he wants his family safe.

“I’m anxious about the decision from (the UK visa office), worried we might have to do more, worried about if flights are still going to be available when (or) if the visa application is approved,” he told the PA news agency.

“I’m anxious about having to pack up five or six years’ worth of our life and move it to storage or get rid of it.

“I’m worried about the timeframe and how long things could still take… worried and anxious is the best way to describe how I’m feeling at the moment.”

Mr Rossiter said he has noticed anxiety in Ukrainian locals has heightened amid the prospect of war.

“At the moment it’s stressful, and especially over the past week or so more Ukrainians do seem to be a bit worried about what’s happening with Russia,” he said.

“But in day-to-day life, everybody is just carrying on as normal – what else can they do?

“Me personally, I don’t want Lena or Leo to be here as things progress.”

But a British business investor living in Ukraine has said he will not be leaving the country in a bid to “engender the sense that Britain really sticks by Ukraine”.

Daniel Williams, 45, is from the Isle of Wight but now lives in Kyiv with his wife and young daughter, who he plans to fly to Manchester with on Friday – before returning to Ukraine at the beginning of March.

Mr Williams, an investor in four eco-friendly businesses across Ukraine, told the PA: “I’ll probably come back solo.

“Ukraine doesn’t need another westerner bailing on her… someone needs to be here to help the economy, which will take a beating now.”

“I’ll come back early March and do all I can with my meagre resources to help small business here, to engender the sense that Britain really sticks by Ukraine,” he said.

Mr Williams added he believes there will not be a march on Kyiv, but a “slow strangulation of Ukraine’s economy”.

And despite claims from Russian ambassador Andrei Kelin that UK diplomacy efforts have resulted in no “constructive solutions” to avert war, Mr Williams maintains pro-British sentiment is high among the locals in Ukraine.

“It is higher than I’ve known right now,” he said.

“Whatever officials say, Britain doesn’t get the same vitriol about inaction as the other Western powers if you talk to normal Ukrainians.

“If the UK acts and supports Ukraine there is a huge opportunity for both countries… (and) if Kyiv stands there’s a wide open goal here for the UK in terms of securing future trade and key mineral assets.”

The Prime Minister warned on Tuesday that Moscow sending troops into the Donbas region under the guise of being “peacekeepers” appears to be the Kremlin “establishing the pretext for a full-scale offensive”, with nearly 200,000 troops now amassed on Ukraine’s border.