Foreign Secretary Liz Truss has told Nato there is “no time for false comfort” over a dampening in the Russian offensive in Ukraine as she is expected to push the defensive alliance to keep up pressure on the Kremlin.

New UK sanctions were announced on Wednesday against Russian banks and oligarchs, which Ms Truss said were among the toughest yet.

While militarily, The Times reported the UK was considering sending armoured vehicles to aid the Ukrainian forces.

But senior Tory Tobias Ellwood said the Government should stop saying the aid being offered was simply defensive, and concentrate on providing more help instead of semantics.

The UK and Nato allies have been wary to insist that any help offered to Ukraine is only so the country can defend itself against the Russian invasion, to try to avoid being drawn into a direct conflict with Russia.

However, the Czech Republic reportedly became the first Nato country to promise to send tanks to help push back against the Russians.

Defence Select Committee chairman Tobias Ellwood told Channel 4 News there was “nothing defensive” about the weaponry already provided to Ukraine, which he said he used while serving in the armed forces.

“There’s nothing defensive about anti-tank weapons, there’s nothing defensive about a rifle. These are offensive weapons and I can’t believe we’re still having semantic debates about this,” Mr Ellwood said.

“We see the Czech Republic now wanting to give tanks, that’s what the Ukrainians are asking for, Poland wanted to move its MiG-29s (fighter jets) across as well. This is the sort of activity that we need to be looking at.”

He said the UK could be providing a humanitarian corridor from the port of Odesa through to international waters.

“That would be a robust stance to take against Russia,” Mr Ellwood said.

Nato secretary general Jens Stoltenberg confirmed that some members of the alliance had sent heavy weaponry to Ukraine following reports the Czech Republic had supplied Soviet-era tanks to Kyiv.

The Times reported that plans were being drawn up which could see armoured vehicles from the UK sent to Ukraine, with British troops stationed in a neighbouring country to provide training.

At a working dinner on Wednesday, the Foreign Secretary told her Nato counterparts the defensive alliance must toughen its response and not allow security vacuums to emerge.

She said: “The age of engagement with Russia is over. We need a new approach to security in Europe based on resilience, defence and deterrence. There is no time for false comfort. Russia is not retreating, but regrouping and repositioning to push harder in the east and south of Ukraine.”

She said the 1997 Nato-Russia Founding Act, in which it was declared the two sides “do not consider each other as adversaries”, is dead.

Earlier, Ms Truss announced new sanctions with asset freezes imposed on Sberbank, Russia’s largest bank, and the Credit Bank of Moscow.

All new outward investment to Russia has been banned and the UK has also committed to end all imports of Russian coal and oil by the end of the year, with gas to follow as soon as possible.

Imports of Russian iron and steel products will be banned and a further eight oligarchs have also been added to the sanctions list.

Ms Truss said they are “some of our toughest sanctions yet”.

The announcement coincided with a parallel move against Sberbank by the US which is also sanctioning Vladimir Putin’s two adult daughters, Mariya Putina and Katerina Tikhonova, and other members of the Russian elite.

Earlier the European Commission set out proposals for a fifth round of sanctions, including a ban on coal imports, for approval by EU ambassadors.

Meanwhile, Boris Johnson said the actions of Russian forces in Ukraine appeared close to “genocide”.

Speaking during a visit to a hospital in Welwyn Garden City, Mr Johnson said: “I’m afraid, when you look at what’s happening in Bucha, the revelations that we are seeing from what Putin has done in Ukraine, which doesn’t look far short of genocide to me, it is no wonder people are responding in the way that they are.”

Western officials warned such atrocities may be “widespread” pointing to the “toxic information climate” in Russia with calls for the “de-nazification” of Ukraine, with former president Dmitri Medvedev, still a close ally of Mr Putin, likening it to the Third Reich.

“When you combine that with a force which is failing and failing badly in an operation for which it was perhaps psychologically underprepared, it just a toxic mix,” one official said.

“The responsibility for this lies with the perpetrators of the acts but it also lies with the Russian leadership. Not only did they order the invasion, they set the tone and the context for this operation as well.”

Elsewhere, Attorney General Suella Braverman praised Ukraine’s investigation into alleged war crimes committed by Russia, which she said had catalogued thousands of cases and identified hundreds of suspects.

Writing in The Times, Ms Braverman warned the “criminal cowards that desecrated Bucha” that they “should not rest easy in your beds”.

Ministers from Nato countries are set to meet in Brussels on Thursday, followed by a press conference with Mr Stoltenberg.