LIZ Truss has suggested it is “very unlikely” that British soldiers will fight alongside Ukrainians in the event of a Russian invasion as she announced “improved legislation” to toughen up sanctions against the Kremlin was imminent.

Fears have been raised that Vladimir Putin is lining up an invasion of Ukraine, with thousands of Russian troops gathered on the border.

Nato secretary-general Jens Stoltenberg has suggested that its troops will not be sent in if Russia moves to invade Ukraine but stressed that efforts to tighten sanctions are being ramped up – stressing there will be a “high price for them to pay with economic and political sanctions”.

The UK Foreign Secretary was asked on the BBC’s Sunday Morning programme if she could rule out a scenario with British soldiers “on the ground”.

Ms Truss said: “That’s very unlikely … and the Defence Secretary has been clear about that.”

Pressed on whether there is any scenario in which “British soldiers are fighting with Ukrainians” against Russian troops, she said: “That is very unlikely.

“This is about making sure that the Ukrainian forces have all the support we can give them, whether it’s intelligence support, whether it’s cyber support, whether it’s defensive weapons, which we have been supplying into Ukraine.”

The Foreign Secretary warned it is “highly likely” that Russian president Vladimir Putin is looking to invade Ukraine.

She added: “That is why we’re doing all we can through deterrence and diplomacy to urge him to desist. That’s why we are strengthening our sanctions regime here in the United Kingdom.

“We’re also supplying and offering extra support into our Baltic allies across the Black Sea, as well as supplying the Ukrainians with defensive weapons.

“And the United Kingdom … is the largest contributor to Nato in Europe and we are the largest European Nato supporter of troops and defences in Europe.”

Ms Truss said that the UK Government will announce “improved legislation” on sanctions so it can “target more Russian interests that are of direct relevance to the Kremlin”.

She told Sky News’s Trevor Phillips On Sunday programme: “We are offering to deploy extra troops into Estonia.

“We are providing more air support across the Black Sea and we’re supplying defensive weapons to Ukraine to make sure that they are in the best possible position should Vladimir Putin try to stage an incursion.

“What I’ll be announcing later this week is improved legislation on sanctions so we can target more Russian interests that are of direct relevance to the Kremlin, because we absolutely need to stop this happening. That is our number one priority.”

She added: “Of course, we’ll use diplomacy. I’m travelling to Ukraine this week. I’ll be travelling to Moscow next week.

“However, the number one thing that will stop Vladimir Putin taking action is if he understands the costs of that action. This could result in a quagmire and he should be well aware of that.”

Pressed over how sanctions can be tightened to see off any threat of a Ukrainian invasion amid concerns that the Russian state is intertwined in the UK economy, Ms Truss insisted an overhaul will ensure “there will be nowhere to hide for Putin’s oligarchs”.

She added: “Currently, the economic sanctions are fairly narrowly drawn, so we could only target companies with a direct involvement in destabilising Ukraine.

“What we are looking to do is widen that so any company of interest to the Kremlin and the regime in Russia would be able to be targeted, so there will be nowhere to hide for Putin’s oligarchs, for Russian companies involved in propping up the Russian state. That’s what we are looking at doing this week.”