Speaking on Sky News this morning, Foreign Secretary Liz Truss has defended the UK’s “very serious package” of sanctions against Russia.

She argued that the current sanctions will be effective in “inflicting pain” on Vladimir Putin.

She also said the Government will ramp up punitive measures in the event of a “full-scale invasion” by Moscow.

Truss told Sky News: “What it will achieve is inflicting pain on Vladimir Putin and his regime, and the Russian economy.

“It is a very serious package. It targets key oligarchs, we’re clear that sovereign debt will not be able to be raised by the Russian government. It targets key Russian banks that fund the military and fund the activities of the Russian government.

“But we are aligned with our international allies in saying that we will escalate the sanctions, that there will be even more tough sanctions on key oligarchs, on key organisations in Russia, limiting Russia’s access to the financial markets, if there is a full-scale invasion of Ukraine, which I’m afraid to say … we are very much expecting.”

She continues to explain there is not yet “full evidence” that Russian troops have incurred on Ukraine.

Asked what would constitute a “full invasion”, she told Sky News: “Well, it constitutes troops crossing the border.”

When it was suggested to her this has already happened, Ms Truss said: “That is frankly ambiguous at this stage.”

She added: “We’ve heard from Putin himself that he is sending in troops. We don’t yet have the full evidence that that has taken place. What we are expecting, and this has been confirmed by the Americans as well as by the United Kingdom, is a full-scale invasion, including potentially of Kyiv.”

This comes as Boris Johnson is pressed to put stricter sanctions on Russia.

The Prime Minister is likely to come under fire in the Commons on Wednesday over the punishment doled out to Kremlin-linked oligarchs and banks in response to Russian aggression.

No 10 has insisted there was more to come if Russia did not back down from manoeuvres in eastern Ukraine where troops had been sent into the Donbas region under the guise of being “peacekeepers”.

Writing in The Times, Truss said the UK was considering sanctions for members of the Russian Duma and Federation Council, and extending Crimea’s territorial sanctions to the separatist controlled territories in the Donbas.

She said: “We have a long list of those complicit in the actions of the Russian leadership. Should Russia refuse to pull back its troops we can keep turning up the heat, targeting more banks, elites and companies of significance.”

Truss added the UK was also willing to introduce “measures to limit Russia’s ability to trade and prohibit a range of high-tech exports, degrading the development of its military industrial base for years”.